Exhibit 99.1

NI 43-101 Technical Report on

Highland Valley Copper Operations

British Columbia

Prepared For:

Teck Resources Limited

Prepared By:

Mr. Christopher Hercun, P.Eng. 

Mr. Alex Stewart, P.Geo. 

Mr. Tim Tsuji, P.Eng. 

Mr. Frank Laroche, P.Eng. 

Mr. Carl Diederichs, P.Eng.

Effective Date:

1 July, 2025

CERTIFICATE OF QUALIFIED PERSON

I, Christopher Hercun, P.Eng., am employed as the Superintendent, Strategic Planning, Teck Highland Valley Copper Partnership, with a site address at Highland Valley Rd, Logan Lake, B.C. Canada, VOK 1WO.

This certificate applies to the technical report titled “NI 43-101 Technical Report on Highland Valley Copper Operations, British Columbia” that has an effective date of 1 July, 2025 (the “technical report”).

I am a Professional Engineer of Engineers and Geoscientists British Columbia; License Number 41498. I graduated from Montana Technological University with a degree in Mining Engineering in 2010.

I have practiced my profession for fifteen years. I have been directly involved in various operational roles at Teck. Relevant experience includes mine planning, geology, geometallurgy, closure planning, project engineering and management, risk management, environmental studies, permitting, economic analysis and business planning.

As a result of my experience and qualifications, I am a Qualified Person as defined in National Instrument 43–101 Standards of Disclosure for Mineral Projects (NI 43–101) for those sections of the technical report that I am responsible for preparing.

I work at the Highland Valley Copper Operations on a daily basis, and this familiarity with the operation serves as my scope of personal inspection.

I am responsible for Sections 1.1, 1.2, 1.3, 1.4, 1.6, 1.9, 1.17 (excepting tailings storage), 1.18, 1.19, 1.20, 1.21, 1.22, 1.23, 1.24, 1.25; Sections 2.1, 2.2, 2.3, 2.4.1, 2.5, 2.6, 2.7; Section 3; Section 4; Section 5; Section 6; Section 12.3.1; Section 18 (excepting 18.6); Section 19; Section 20; Section 21; Section 22; Section 24; Sections 25.1, 25.2, 25.3, 25.12 (excepting tailings storage), 25.13, 25.14, 25.15, 25.16, 25.17, 25.18, 25.19; Section 26; Section 27; and Appendix A of the technical report.

I am not independent of Teck Resources Limited, as independence is described by Section 1.5 of NI 43–101.

I have been involved with the Highland Valley Copper Operations since 2013.

I have read NI 43–101 and the sections of the technical report for which I am responsible have been prepared in compliance with that Instrument.

Teck Resources Limited

Suite 3300, Bentall 5, 550 Burrard Street, Vancouver, British Columbia, V6C0B3

www.teck.com

As of the effective date of the technical report, to the best of my knowledge, information and belief, the sections of the technical report for which I am responsible contain all scientific and technical information that is required to be disclosed to make those sections of the technical report not misleading.

Dated this 10th day of November 2025.

“signed and sealed”

Christopher Hercun, P.Eng.

Teck Resources Limited

Suite 3300, Bentall 5, 550 Burrard Street, Vancouver, British Columbia, V6C0B3

www.teck.com

CERTIFICATE OF QUALIFIED PERSON

I, Alex Stewart, P.Geo., am employed as the Senior Mine Geostatistician, with the Highland Valley Copper Partnership, with a site address at Highland Valley Rd, Logan Lake, B.C. Canada, VOK 1WO.

This certificate applies to the technical report titled “NI 43-101 Technical Report on Highland Valley Copper Operations, British Columbia” that has an effective date of 1 July, 2025 (the “technical report”).

I am a Professional Geoscientist (P.Geo.) with Engineers and Geoscientists BC #42690. I graduated from the Lakehead University with an Honours Bachelor of Science degree in Geology in 1995.

I have practiced my profession for 30 years. I have been directly involved in mining operations, mineral resource and mineral reserve estimation, and analysis at open-pit and underground mines within Canada. I have experience in exploration, drilling program definition, geological mapping, interpretation and modeling, geometallurgical programs, grade estimation, grade control and mine to mill reconciliation.

As a result of my experience and qualifications, I am a Qualified Person as defined in National Instrument 43–101 Standards of Disclosure for Mineral Projects (NI 43–101) for those sections of the technical report that I am responsible for preparing.

I work at the Highland Valley Copper Operations on a daily basis, and this familiarity with the operation serves as my scope of personal inspection.

I am responsible for Sections 1.1, 1.2, 1.5, 1.6, 1.7, 1.8, 1.9, 1.11, 1.12; Sections 2.1, 2.2, 2.3, 2.4.2, 2.5, 2.6, 2.7; Section 3; Section 7; Section 8; Section 9; Section 10; Section 11; Sections 12.1, 12.2, 12.3.2; Section 14; Section 23; Sections 25.1, 25.4, 25.5, 25.6, 25.8; Section 26; and Section 27 of the technical report.

I am not independent of Teck Resources Limited, as independence is described by Section 1.5 of NI 43–101.

I have been involved with the Highland Valley Copper Operations since 2011.

I have read NI 43–101 and the sections of the technical report for which I am responsible have been prepared in compliance with that Instrument.

Teck Resources Limited

Suite 3300, Bentall 5, 550 Burrard Street, Vancouver, British Columbia, V6C0B3

www.teck.com

As of the effective date of the technical report, to the best of my knowledge, information and belief, the sections of the technical report for which I am responsible contain all scientific and technical information that is required to be disclosed to make those sections of the technical report not misleading.

Dated this 10th day of November 2025.

“signed and sealed”

Alex Stewart, P.Geo.

Teck Resources Limited

Suite 3300, Bentall 5, 550 Burrard Street, Vancouver, British Columbia, V6C0B3

www.teck.com

CERTIFICATE OF QUALIFIED PERSON

I, Tim Tsuji, P.Eng., am employed as the Chief Mine Engineer, Strategic Planning, Teck Highland Valley Copper Partnership, with a site address at Highland Valley Rd, Logan Lake, B.C. Canada, VOK 1WO.

This certificate applies to the technical report titled “NI 43-101 Technical Report on Highland Valley Copper Operations, British Columbia” that has an effective date of 1 July, 2025 (the “technical report”).

I am a Professional Engineer of Engineers and Geoscientists British Columbia; License Number 37762. I graduated from the University of British Columbia with a Bachelor of Applied Science degree in Mining and Mineral Processing Engineering (Mining Option) in 2000.

I have practiced my profession for 21 years. I have been directly involved in mine design and mine planning at Highland Valley Copper for 13 years and Mineral Reserve and Mineral Resource estimation for 11 of those years.

As a result of my experience and qualifications, I am a Qualified Person as defined in National Instrument 43–101 Standards of Disclosure for Mineral Projects (NI 43–101) for those sections of the technical report that I am responsible for preparing.

I work at the Highland Valley Copper Operations on a daily basis, and this familiarity with the operation serves as my scope of personal inspection.

I am responsible for Sections 1.1, 1.2, 1.9. 1.13, 1.14, 1.15 (except geotechnical and hydrogeological); Sections 2.1, 2.2, 2.3, 2.4.3, 2.5; Section 3; Section 12.3.3; Section 15; Sections 16.1, 16.4, 16.5, 16.6, 16.7, 16.8, 16.9, 16.10, 16.11; Sections 25.1, 25.6, 25.9, 25.10; Section 26; and Section 27 of the technical report.

I am not independent of Teck Resources Limited, as independence is described by Section 1.5 of NI 43–101.

I have been involved with the Highland Valley Copper Operations since 2012.

I have read NI 43–101 and the sections of the technical report for which I am responsible have been prepared in compliance with that Instrument.

Teck Resources Limited

Suite 3300, Bentall 5, 550 Burrard Street, Vancouver, British Columbia, V6C0B3

www.teck.com

As of the effective date of the technical report, to the best of my knowledge, information and belief, the sections of the technical report for which I am responsible contain all scientific and technical information that is required to be disclosed to make those sections of the technical report not misleading.

Dated this 10th day of November 2025.

“signed and sealed”

Tim Tsuji, P.Eng.

Teck Resources Limited

Suite 3300, Bentall 5, 550 Burrard Street, Vancouver, British Columbia, V6C0B3

www.teck.com

CERTIFICATE OF QUALIFIED PERSON

I, Frank Laroche, P.Eng, am employed as the Principal Engineer Mineral Processing, Strategic Planning North America, Teck Resources Limited, with an office address at Suite 3300, Bentall 5, 550 Burrard Street, Vancouver, British Columbia, V6C0B3.

This certificate applies to the technical report titled “NI 43-101 Technical Report on Highland Valley Copper Operations, British Columbia” that has an effective date of 1 July, 2025 (the “technical report”).

I am a Professional Engineer (P.Eng) registered with Engineers and Geoscientists of British Columbia (EGBC); License Number 55606. I graduated from McGill University with a bachelor's degree in Materials Engineering in 2008.

I have practiced my profession for 17 years. I have been directly involved in site visits and inspected all current stages of mineral processing, including crushing, grinding, flotation, leaching, and dewatering. I’ve contributed to geometallurgical programs through sample selection, managing test work and data analysis. I’m directly involved in the design and ongoing reconciliation of the copper recovery and throughput modeling.

As a result of my experience and qualifications, I am a Qualified Person as defined in National Instrument 43–101 Standards of Disclosure for Mineral Projects (NI 43–101) for those sections of the technical report that I am responsible for preparing.

I work at the Highland Valley Copper Operations on a daily basis, and this familiarity with the operation serves as my scope of personal inspection.

I am responsible for Sections 1.1, 1.2, 1.9, 1.10, 1.16; Sections 2.1, 2.2, 2.3, 2.4.4; Section 3; Section 12.3.4; Section 13; Section 17; Sections 25.1, 25.7, 25.11; Section 26; and Section 27 of the technical report.

I am not independent of Teck Resources Limited, as independence is described by Section 1.5 of NI 43–101.

I have been involved with the Highland Valley Copper Operations since 2008.

I have read NI 43–101 and the sections of the technical report for which I am responsible have been prepared in compliance with that Instrument.

Teck Resources Limited

Suite 3300, Bentall 5, 550 Burrard Street, Vancouver, British Columbia, V6C0B3

www.teck.com

As of the effective date of the technical report, to the best of my knowledge, information and belief, the sections of the technical report for which I am responsible contain all scientific and technical information that is required to be disclosed to make those sections of the technical report not misleading.

Dated this 10th day of November 2025.

“signed and sealed”

Frank Laroche, P.Eng.

Teck Resources Limited

Suite 3300, Bentall 5, 550 Burrard Street, Vancouver, British Columbia, V6C0B3

www.teck.com

CERTIFICATE OF QUALIFIED PERSON

I, Carl Diederichs, P.Eng., am employed as the Superintendent, Geotechnical, Teck Highland Valley Copper Partnership, with a site address at Highland Valley Rd, Logan Lake, B.C. Canada, VOK 1WO.

This certificate applies to the technical report titled “NI 43-101 Technical Report on Highland Valley Copper Operations, British Columbia” that has an effective date of 1 July, 2025 (the “technical report”).

I am a Professional Engineer of Engineers and Geoscientists British Columbia; License Number 39796. I graduated from Geological Engineering at the University of British Columbia in 2008.

I have practiced my profession for seventeen years since graduation. I have been directly involved in engineering design, planning and operations at Highland Valley Copper Operations between 2008–-2010 and 2012–current.

As a result of my experience and qualifications, I am a Qualified Person as defined in National Instrument 43–101 Standards of Disclosure for Mineral Projects (NI 43–101) for those sections of the technical report that I am responsible for preparing.

I work at the Highland Valley Copper Operations on a daily basis, and this familiarity with the operation serves as my scope of personal inspection.

I am responsible for Sections 1.1, 1.2, 1.15 (geotechnical and hydrogeological only), 1.17 (tailings storage only); Sections 2.1, 2.2, 2.3, 2.4.5; Section 3; Section 12.3.5; Sections 16.2, 16.3; Section 18.6; Sections 25.1, 25.6, 25.12 (tailings storage only); Section 26; and Section 27 of the technical report.

I am not independent of Teck Resources Limited, as independence is described by Section 1.5 of NI 43–101.

I have been involved with the Highland Valley Copper Operations since 2008.

I have read NI 43–101 and the sections of the technical report for which I am responsible have been prepared in compliance with that Instrument.

Teck Resources Limited

Suite 3300, Bentall 5, 550 Burrard Street, Vancouver, British Columbia, V6C0B3

www.teck.com

As of the effective date of the technical report, to the best of my knowledge, information and belief, the sections of the technical report for which I am responsible contain all scientific and technical information that is required to be disclosed to make those sections of the technical report not misleading.

Dated this 10th day of November 2025.

“signed and sealed”

Carl Diederichs, P.Eng.

Teck Resources Limited

Suite 3300, Bentall 5, 550 Burrard Street, Vancouver, British Columbia, V6C0B3

www.teck.com

Table Of Contents

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List Of Tables

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List Of Figures

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Appendix A

Appendix A: Detailed Mineral Tenure Table and Mineral Tenure Location Maps

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TOC x

 

Mr. Christopher Hercun, P.Eng., Mr. Alex Stewart, P.Geo., Mr. Tim Tsuji, P.Eng., Mr. Frank Laroche, P.Eng., and Mr. Carl Diederichs, P.Eng. prepared this technical report (the Report) for Teck Resources Limited (Teck) on the wholly-owned Highland Valley Copper Operations (Highland Valley Copper or the Project), located in British Columbia, Canada.

Teck uses a subsidiary, Teck Highland Valley Copper Partnership (Highland Valley Copper Partnership), as the operating entity for the Highland Valley Copper Operations.

The Report was prepared to support Teck’s news release dated 23 July 2025, entitled “Teck Announces Construction of Highland Valley Copper Mine Life Extension to Proceed”.

Teck commenced the permitting application process for the life-of-mine (LOM) plan described in this Report in 2019. The initial application referred to the mine plan as the Highland Valley Copper 2040 Project (HVC 2040), later changing to the HVC Mine Life Extension Project (HVC MLE). The permits were granted in 2025, and the permitted mine life extension project is the LOM plan in this Report.

Mineral Resources and Mineral Reserves are estimated for the Valley, Lornex, Highmont, and Bethlehem deposits.

Mineral Resources and Mineral Reserves are reported using the confidence categories in the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Definition Standards for Mineral Resources and Mineral Reserves (May 2014; the 2014 CIM Definition Standards).

The Mineral Resource and Mineral Reserve estimates are forward-looking information and actual results may vary. The risks regarding Mineral Resources and Mineral Reserves are summarized in the Report (see Section 14, Section 15, and Section 25). The assumptions used in the Mineral Resource estimates are summarized in the footnotes of the Mineral Resource table and outlined in Section 14 of the Report. The assumptions used in the Mineral Reserve estimates are summarized in the footnotes of the Mineral Reserve table and outlined in Section 15 and Section 16 of the Report.

Currency is expressed in Canadian dollars (C$) unless stated otherwise.

Units presented are typically metric units, such as metric tonnes, unless otherwise noted.

The Report uses Canadian English.

The Highland Valley Copper Operations are located approximately 75 km southwest of Kamloops, British Columbia (BC) and 17 km west of the town of Logan Lake, BC.

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The operations are readily accessible by paved highway, including from Vancouver via Highway 1 to Highway 5 (the Coquihalla Highway) to Merritt, and then via Highway 97C to Logan Lake and the Highland Valley Copper Operations. Highway 97C also connects the site to Ashcroft, location of the railway terminal for copper concentrate handling. Services offered at Ashcroft include bulk, break-bulk, and container (forthcoming) handling. Passenger rail services provided by VIA Rail and Canadian Pacific are available in Kamloops. There are three airports within the Thompson–Nicola Regional District, one of which provides commercial services.

The climate is characterized as semi-arid, characterized by warm summers, cold winters, and the lack of a distinct wet season or dry season. Mining operations are conducted year-round.

The mine is located within the approximately 23 km long Highland Valley, at the lower elevation end of the Thompson Plateau in the southern Interior Plateau region of BC, on the eastern slope of the Pacific Coastal Mountains. The Highland Valley is bounded on the west by the Thompson River, and on the east by the Guichon Creek Valley. The mineral tenure area ranges in elevation from 1,000–1,750 metres above sea level (masl) with the highest elevations occurring in the southwestern part of the area. The mining operations are situated at approximately 1,280 masl. Vegetation varies depending on moisture availability, elevation, and aspect, and typically consists of fire-dominated, dry-land vegetation.

The Thompson–Nicola Regional District has a history of development and land use that includes forestry, ranching, and mining dating back to the early 1900s. It currently supports substantial urban settlement, mining, forestry, agriculture recreation, and transportation including several highway and railway corridors.

The Project area is included in the General Resource Management Zone defined under the Kamloops Land and Resource Management Plan, within which mineral development is identified as an allowable land use.

The Highland Valley is a significant area for Indigenous Peoples who have historically occupied the area and continue to use it today. Primary and traditional uses include but are not limited to: hunting, fishing, gathering, other cultural and spiritual purposes, agriculture, and livestock watering. The Highland Valley Copper mine site is located within the unceded territory of the Nlaka’pamux Nation, and the Secwépemc Nation also have interests in the area.

The mineral tenure area consists of 941 active mineral claims (55,625 ha), 106 active mining leases (3,391.1 ha) and 18 active Crown grants (private mineral holdings; 1,237.9 ha) that collectively cover about 60,254 ha. All tenure is held 100% in the name of the Teck subsidiary Teck Highland Valley Copper Partnership. The mineral claims and mining leases are renewed annually, per the BC Mineral Tenure Act. Crown grants are an interest in land as a fee simple estate in ownership. These rights are held in perpetuity by Highland Valley Copper if the assessed property and mineral taxes are paid annually. All required payments were current at the Report effective date.

Surface rights in the Project general area are held 100% in the name of Teck Highland Valley Copper Partnership. Additional land acquisition may be required for easements to support the LOM plan.

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Teck currently holds 26 active BC water licences in the name of Teck Highland Valley Copper Partnership that have expiry dates ranging from 2026–2053. Water licences are renewed as necessary per the BC Water Sustainability Act.

There are no royalties, back-in rights, payments or other agreements outside of the percentage distributions of the Teck Highland Valley Copper Partnership on claims held to cover the Highmont, Valley and Lornex open pits.

The Highland Valley deposits are considered to be classic examples of porphyry copper–molybdenum deposits.

The Project is situated within the allochthonous Quesnel island arc terrane. Intrusions belonging to the Lower Jurassic Guichon Suite are a major component of the Quesnel terrane. Plutonism migrated from west to east during the formation of the upper Triassic to lower Jurassic Nicola Group, with the Guichon Creek Batholith representing the oldest, and westernmost intrusion belt of the Quesnel terrane. The intrusive rocks are spatially related to the volcano–sedimentary units of the Nicola Group.

The Guichon Creek Batholith extends over an approximate area of 60 x 30 km. It is a north–northwest elongated multi-phase intrusion with major compositional variations that evolve from an older mafic margin inward to a younger and generally more felsic core. Contacts between the phases, though locally sharp, are commonly gradational and define an annular zoning with the older phases towards the outer margins of the batholith and the younger phases within the central area. The phases are nearly concentric in plan view. Numerous syn- to post-mineralization porphyritic to aplitic dykes and stocks cut the main intrusive facies with the highest density occurring primarily within and adjacent to the porphyry deposits. The porphyry deposits are hosted either in younger phase rocks, or in dyke swarms and intrusive breccias associated with the younger phase rocks.

The batholith is elongated northward and segmented by major north- and northwest–west-striking faults that are closely related to mineralization. The major northerly-trending structures include the central Lornex fault, the bounding Guichon Creek fault to the east, and the Western Boundary Fault to the west. Northwesterly-trending structures include the Skuhun Creek, Highland Valley, and Barnes Creek faults. Dykes appear to preferentially occupy large-scale tension fractures that have similar orientations to the major fault directions.

Adjacent to the batholith contact, a metamorphic halo up to 500 m wide developed. Close to the batholith contact, assemblages are typical of the hornblende hornfels facies; further out, albite–epidote facies are typical.

Distal alteration includes green sericite, epidote, and chlorite, as veins and as fracture coatings. The type of vein alteration developed can reflect host rock composition; green sericite veins characterise the more felsic Bethlehem, Skeena, and Bethsaida phases, but chlorite (epidote) veins are more common in the earlier, more mafic batholith phases. Moderately to strongly developed distal alteration zones surround each of the five main deposits. Proximal alteration and veining types include a barren core of intense quartz veining, potassic (potassic feldspar and hydrothermal biotite) and phyllic. These are overprinted by late, structurally-controlled argillic alteration.

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The major deposits are located in the centre of the batholith, and include the Valley, Lornex, Highmont, Bethlehem, and JA deposits. All of the deposits except the JA deposit have been, or are being mined; JA remains undeveloped.

Significant copper mineralization occurs in a number of stages. The oldest followed the emplacement of Bethlehem granodiorite sub-facies and coincided with dyke intrusion and breccia formation in the Bethlehem area; the Bethlehem mineralization is dated ca 209 Ma. The second phase, dated at ca 208 Ma, followed emplacement of the Skeena sub-facies and Bethsaida granodiorite sub-facies. The Valley, Lornex, and Highmont systems formed at this time.

Most of the sulphide mineralization is developed in fractures, veins, faults, or breccia bodies. Higher copper grades typically occur where the fracture density is high or where several sets of fracture swarms overlap. The first copper-mineralizing event followed the formation of the Bethlehem facies, and occurred with the emplacement of porphyry dykes and breccias into this facies, forming the Bethlehem deposit. The second, and larger, copper–molybdenum mineralizing event followed the emplacement of the Bethsaida facies and resulted in the formation of the Valley–Lornex and Highmont deposits.

The originally contiguous Valley–Lornex deposit was cut by the late-stage Lornex fault, offsetting the Valley and Lornex deposits by about 3.5 km.

The lateral extents of the Valley deposit are generally well defined, but the deposit remains open locally at depth. Mineralization at the Lornex deposit remains open to the south, southeast and at depth. Beneath the Lornex deposit there is considerable potential to extend mineralization as the high-clay and sericite alteration as well as the higher pyrite content compared to the Valley deposit suggests that the Lornex mineralization is a higher-level expression of the system. The lateral extents of the Highmont deposit are generally well defined except to the east. Mineralization also locally remains open at depth within the Highmont deposit. As the Highmont deposit contains multiple mineralized porphyry centres it is possible for additional porphyry centres to be discovered in the area. The Bethlehem deposit is generally well constrained, with limited depth potential. Jersey North is an occurrence located about 400 m to the north of the Jersey pit, and has been tested with multiple drill holes returning encouraging results. Mineralization remains open to the south of the Iona pit. As the Bethlehem deposit contains multiple mineralized porphyry centres it is also possible for additional porphyry complexes to be discovered in the area. Potential to discover additional porphyry bodies within the mine area remains, particularly beneath areas of Tertiary volcanic or recent glacial cover.

The Project has a long development and exploration history. Prior to the 100% acquisition by Teck of the Highland Valley Copper Partnership in 2004, the following individuals, joint ventures and companies had Project involvement: Egil Lorentzen, Huestis–Reynolds Syndicate, Bethlehem Copper Corporation, Ltd., American Smelting and Refining Co. (Asarco), Kenneco Exploration, Huestis Mining Company, Cominco Ltd., Highmont Mining Corp. Ltd., Rio Tinto Ltd., Yukon Consolidated, Lornex Mining Company, Rio Algom Ltd., Billiton plc, later BHP Billiton plc, and various iterations of the Highland Valley Copper Partnership (initially Cominco Ltd., Rio Algom Ltd., Teck Corporation, and Highmont Mining Ltd.; later Teck Cominco Ltd., Billiton, and Highmont Mining Ltd., and subsequently BHP Billiton and Teck). Work completed included claims staking, regional geological mapping, prospect identification, induced polarization ground geophysical surveys, drilling, underground development, mining studies, and open pit mining. Mined open pits included the Huestis, Jersey, and Iona pits in the Bethlehem area, the Lornex and Valley open pits and the Highmont open pit.

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Following acquisition of the 100% ownership interest, Teck completed district and prospect-scale mapping, geochemical sampling (soil, rock chip and grab), airborne and ground geophysical surveys, core and reverse circulation (RC) drilling, environmental, geotechnical, metallurgical, and mining studies, metallurgical testwork, and open pit mining.

As at the Report effective date of 1 July, 2025, a total of 4,127 drill holes (805,749 m) were completed across the mineral tenure area. Of the total drilling, there are 2,805 core holes (682,523 m), 518 percussion drill holes (33,343 m), 55 RC drill holes (4,972 m), eight sonic drill holes (661 m), and 741 unknown drill holes (84,250 m). Unknown methods represent drilling completed for distinct drill programs and overburden delineation or geotechnical instrumentation purposes.

Close-out dates for the databases supporting Mineral Resource estimation vary by deposit. Drilling supporting the Valley estimate was completed between 1966–2024 and totals 748 drill holes (220,099 m); the database was closed as at 22 July, 2024. Drilling supporting the Lornex estimate was completed between 1965–2024 and totals 461 drill holes (104,846 m). The database was closed as at 22 June, 2024. Drilling supporting the Highmont estimate was completed between 1966–2024 and totals 422 drill holes (76,924 m); the database close-out date was 10 August, 2023. Drilling supporting the Bethlehem estimate was completed between 1970–2015 and totals 587 drill holes (154,873 m); the database was closed as at 31 March, 2016.

The RC chips collected in 2015–2016 were logged by geologists following Teck practices, and record mineralogy, alteration, and mineralization styles at 1.5 m intervals.

Currently, geomechanical logging of core holes is performed by core technicians, followed by geological logging and sampling by geologists. Geological logging intervals vary based on lithological, alteration, and mineralization variability, with a minimum sample length of 0.5 m. All significant structural features are recorded regardless of length. Specific gravity and point load tests are conducted approximately every 15 m downhole. Sample intervals are defined by logging geologists, with lengths ranging from 0.5–3.0 m. Once sample tags are placed, the core is photographed dry.

Core recovery across all four deposit areas (Valley, Lornex, Highmont, and Bethlehem) has generally been acceptable, ranging from >88 to >94%. Intervals of low recovery are typically associated with fault zones, pre-mining surface exposure, or blast-related damage.

Historical drill collar surveys were taken by theodolites and total station instruments. Under current practices, drill collar locations are typically recorded using high-precision global positioning system instruments. For angled drill holes, as-built surveys are conducted using total station instruments to ensure accurate collar orientation and positioning. Unmanned aerial vehicle (UAV) photogrammetry is completed over the open pits, from which 3D photogrammetric maps of pit topography are generated. The UAV is also used to provide video footage for mine planning and pit inspections. Laser scanning is used for 3D mapping of pit walls, and to survey geotechnically sensitive areas.

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Currently, downhole surveys are conducted using a Reflex single-shot survey tool. Surveys are typically performed at 60-m intervals on the way into the hole, at the end of the hole, and again at 60-m intervals on the way out, offset from the inbound survey depths where possible, or as permitted by ground conditions.

Grade control at the Highland Valley Copper Operations is managed through systematic blast hole drilling, which provides detailed spatial data to support ore-waste delineation and short-term mine planning. Standardized drill patterns have been employed across the various deposits, with minor adjustments over time to optimize fragmentation, dilution control, and ore recovery.

The orientation and geometry of the porphyry systems vary across the different deposits, influencing drill hole design and sample length representativity.

Since the database close-out dates for the Valley, Lornex, Highmont, and Bethlehem areas, a total of 52 additional core holes (10,792 m) were completed as at 1 July, 2025. The Qualified Person reviewed the available results from this drilling and compared them to the current block model. The results confirm that the observed mineralization widths are consistent with those presented in the Mineral Resource estimate.

RC samples were collected over 1.5 m intervals. Historically, core was commonly sampled as whole core at 3.0 m intervals. Currently, sample intervals vary by core diameter, NQ-diameter core is sampled at 3.0 m intervals, and HQ-diameter core is sampled at 2.0 m intervals. Blast hole drilling is conducted exclusively to support active mining operations and is not used in Mineral Resource estimation.

No historical specific gravity (SG) measurements predating 2010 were identified in the acQuire database. SG data collection commenced in 2010 and continued through 2019 across the four deposit areas. SG determinations were performed by core logging personnel at the Teck core facility using the water displacement method.

Two main primary analytical laboratories provided analytical services, the mine laboratory and the laboratory currently known as Bureau Veritas Commodities Vancouver (Bureau Veritas). The mine laboratory is not independent and is not accredited. It was used as the primary laboratory from the 1960s–2013. Bureau Veritas and its predecessor ACME Analytical Solutions, located in Vancouver, BC, were and are independent; Bureau Veritas holds ISO/IEC17025 accreditations for selected analytical techniques. Bureau Veritas was used from 2013 onwards. The current check assay laboratory is ALS, in North Vancouver, BC, which is an independent laboratory and holds ISO/IEC17025 accreditations for selected analytical techniques.

Sample preparation methods had minor variations between the different laboratories. Samples were typically crushed to 2 mm or 70% passing 2 mm, and pulverized to either 95% passing 106 µm (150 mesh) or 85% passing 75 µm (200 mesh). Analytical methods included:

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Sample security relied, and continues to rely, upon the fact that the samples were always attended or locked at the sample dispatch facility. Chain-of-custody procedures consisted of filling out sample submittal forms that are sent to the laboratory with sample shipments to ensure that all samples were received by the laboratory.

A quality assurance and quality control (QA/QC) program was in place from 2016 onward. This included insertion of standard reference materials (standards), coarse and pulp blanks, and duplicates into the sample stream. Where a quality control sample was outside allowed tolerances it was reviewed by a quality control specialist who could recommend re-assays and/or other remedial actions. The QA/QC programs adequately addressed issues of precision, accuracy, and contamination.

Highland Valley Copper Operations personnel prepare an annual “Resource and Reserve” report that documents the methodologies and data supporting the Mineral Resource and Mineral Reserve estimates for the reporting year. The report includes a comprehensive review of QA/QC and reconciliation data.

Numerous external audits or data collection supervision have been undertaken since 2004; the most recent was in 2025, when both the mine plan and Mineral Resource and Mineral Reserve estimates were audited.

Each Qualified Person undertook data verification in the discipline areas for which they were taking responsibility. No material issues were noted as a result of that verification by any Qualified Person.

A significant number of metallurgical studies and accompanying laboratory-scale and pilot plant tests have been completed. The majority of the early testwork is no longer relevant due to the deposit areas that were tested being mined out. These test programs were sufficient to establish the optimal processing route. The results obtained supported estimation of recovery factors for the various mineralization types.

Either internal metallurgical research facilities operated by the property owner at the time, or external consultants, undertook the testwork and associated research. The testwork facilities performed metallurgical testing using industry-accepted procedures and to industry-accepted standards at the time the testwork was completed. There is no international standard of accreditation provided for metallurgical testing laboratories or metallurgical testing techniques.

Geometallurgical variability testwork programs were conducted between 2013 and 2023 on mineralization from the Bethlehem, Iona, Valley–Lornex, and Highmont areas to support LOM planning. The testwork was performed at independent laboratories, including SGS in Burnaby and ALS in Kamloops. All testwork data and results from these programs were retained.

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The recovery estimates for the LOM are developed using various distinct recovery models. The current structure of the empirical copper recovery model was first developed in 2012 and is periodically refined to reflect additional operating and advancements in orebody knowledge. The empirical copper recovery model is used prior to the addition of C3 ball mill and the D-Auto SAG conversion in the LOM plan and is based on historical operating data. A separate copper recovery model is developed for the remainder of the LOM, based on testwork to simulate the expected flotation performance of a modified mill circuit. This model is only applied after the completion of the grinding and flotation circuit upgrades. A variable model for molybdenum circuit recovery is used, which is based on bulk feed parameters to the circuit. The recovery forecasts for the LOM are provided in Table ‎1-1.

The copper concentrate is not expected to have any notable levels of deleterious elements such as arsenic, antinomy, mercury, zinc, and lead, which will provide HVC a competitive edge.

Mineral Resources were estimated for the Bethlehem, Highmont, Lornex, and Valley deposit areas. Selective mining unit blocks were set for all deposits at 25 x 25 x 15 m.

Rock types were defined based on the current understanding of geology and mineralization controls.

For the Valley deposit, two copper and two molybdenum grade shells were created. The Valley grade shells were restricted by the Lornex fault to the east and overlying overburden–rock surfaces. Two copper grade and two molybdenum grade shells were used for the Lornex deposit. The Lornex grade shells were also restricted by the Lornex fault hanging wall contact to the west and overlying overburden–rock surfaces. One copper grade shell and one molybdenum grade shell were created for the Highmont deposit. At Bethlehem, copper mineralized domains were modeled for two grade domains, and molybdenum mineralized domains were modeled for four grade domains, two each at Iona and Jersey.

Histograms, log probability plots, and descriptive statistics were used to confirm that the composited sample populations in each estimation domain were approximately stationary. Valley mineralized domains were treated as firm to adjacent domains except for the Avalanche domain, which was treated as a hard boundary. Lornex mineralized domains were treated as firm to adjacent domains except for the hanging wall contact of the Lornex fault, which was treated as a hard boundary. Estimation at Highmont used adjacent domain boundaries as firm boundaries, except for the Waterhole fault, which was treated as a hard boundary.

During Bethlehem estimation, the Late Spud Stock, which is a barren unit near Spud Lake, was treated with a hard boundary to prevent grade-smearing.

For the Valley, Lornex, and Highmont block estimates, density values were averaged and assigned by lithology. For the Bethlehem block estimate, density was estimated using inverse distance weighting to the power of two. For the Valley, Lornex and Highmont block estimates a 5 m composite length for grade estimation was selected, as it was the best compatible length option relative to the 15 m block height. For the Bethlehem block estimate, a 6 m composite length for grade estimation was selected.

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Table ‎1-1:      Metallurgical Recovery and Concentrate Grade Forecasts

Note: HVC = Highland Valley Copper; MLE = mine life extension project (LOM plan), dmt = dry metric tonne

Histograms and cumulative frequency distributions were analyzed by grade zone domain to identify high-grade outliers and determine an appropriate capping value for each domain as required. This capping approach was applied for both copper and molybdenum in each domain used in estimation. Most domains were capped.

Variography modelling was completed, and search ellipses for grade estimation were derived from the modelled variograms. Ordinary kriging (OK) was selected as the grade interpolation method for estimation of copper and molybdenum grades using Leapfrog Edge. However, the Valley Avalanche unit grade domains (east of the Lornex fault) were modelled differently, using inverse distance weighting to the second power (ID2), because the Avalanche material is a talus deposit, and it is no longer in situ. All mineralized copper and molybdenum domains at Valley, Lornex, and Highmont were estimated using a two-pass estimation strategy. Unestimated blocks were left as blank grades. Outlier restrictions (high yields) were implemented on the second pass only, and only in the low-grade background domains, to prevent high grade blow-outs. Copper estimation at Bethlehem used five passes, with each pass estimating grades only in previously un-estimated blocks. To prevent over-estimation from high-grade copper outliers, high-grade search restrictions (high yields) were applied. The molybdenum estimation approach used three passes.

At Valley, the number of composites used in the estimation ranged from a minimum of 8–10 samples, and a maximum of 12–25 samples. At Lornex, the number of composites used in the estimation ranged from a minimum of 9–10 samples to a maximum of 16–25 samples, with a maximum of four composites per drill hole for the first pass and five composites per drill hole for the second pass. The number of composites used in the Highmont estimation ranged from a minimum of 9–10 samples, and a maximum of 16–25 samples. The maximum number of composites per drill hole ranged from four per drill hole for the first pass to five per drill hole for the second pass. A minimum of seven and a maximum of 14 composites were used in each estimation pass at Bethlehem.

Block estimates of copper and molybdenum were validated using several methods, including visual validation; comparison between ordinary kriging and nearest neighbour statistics; swath plots; and change of support analysis. No material biases in the estimations were noted.

Drill spacing supporting the Measured Mineral Resource confidence category aimed for ±15% accuracy in quarterly production estimates 90% of the time, albeit modified slightly by also taking into account geological knowledge and mining experience, variography and other statistics, and past reconciliation results. Similarly, the drill spacing recommendations supporting the Indicated Mineral Resource confidence category aimed for ±15% accuracy in annual production estimates 90% of the time, again modified slightly, as it was for the Measured Mineral Resource. The drill spacing recommendations supporting the Inferred Mineral Resource confidence category were based on double the recommended spacings for the Indicated Mineral Resource confidence category.

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Teck uses a copper-equivalent grade (CuEq) for Mineral Resources reporting.

A molybdenum factor is initially determined to represent the economic value of a quantity of molybdenum in the mill feed compared to an equal quantity of copper, calculated in the following formula where charges and costs are expressed in dollars per tonne of payable metal:

Copper-equivalent grade models are then created using the following formula:

The resource-constraining pit shells were based on a Lerchs–Grossmann optimization process using Whittle software, and a set of commodity prices established annually by Teck for Mineral Resources and Mineral Reserves estimation. Potentially-mineable blocks were constrained to claims owned by Teck, limiting the southeastern extent of the Highmont Mineral Resources estimate. Pit shells generated for a revenue factor of 1.0 were used for all areas.

Mineral Resources are reported in situ, using the 2014 CIM Definition Standards. The Mineral Resources estimate has an effective date of 1 July, 2025 (Table ‎1-2).

The Qualified Person for the Mineral Resource estimates is Mr. Alex Stewart, P.Geo., a Teck Highland Valley Copper Partnership employee.

Factors that may affect the Mineral Resource estimates include: metal price and exchange rate assumptions; changes to the assumptions used to generate the copper equivalent cut-off grade; changes in local interpretations of mineralization geometry and continuity of mineralized zones; changes to geological and mineralization shapes, and geological and grade continuity assumptions; density and domain assignments; changes to geotechnical assumptions including pit slope angles; changes to cost assumptions; changes to mining and metallurgical recovery assumptions; changes to the input and design parameter assumptions that pertain to the conceptual pit constraining the estimates potentially amenable to open pit mining methods; and assumptions as to the continued ability to access the site, retain mineral and surface rights titles, maintain environment and other regulatory permits, and maintain the social license to operate.

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Table ‎1-2: Mineral Resources Summary Table

Notes to Accompany the Mineral Resources Table:

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The design reserve pits were based on a Lerchs-Grossmann optimization process using Whittle software and detailed phased pit designs. Twenty mine phases (nine Valley phases, one Lornex, four Highmont, and six Bethlehem) were devised to prioritize the higher-grade zones within the mineral extraction plan, while maintaining suitable working widths that would enable high productivity mining sequences using large-scale mining equipment. Mining assumes conventional open pit operations using truck-and-shovel technology. The size of the open pits and the production rates are controlled by site-specific constraints.

The Whittle inputs that provided the design basis included Inferred Mineral Resources and a reduction in selling costs to represent silver and gold byproduct credits received for the copper concentrate. Although the pit designs used these parameters, all of the Mineral Reserve estimates within this Report have been estimated with Inferred Mineral Resources converted to waste and no revenues were assumed to be provided by silver and gold.

The Lornex and Bethlehem pit optimizations were performed prior to applications for permitting in 2010 and 2016, respectively. The Valley pit is based on a 2023 optimization and the Highmont pit is based on a 2024 optimization. In addition to the limitation imposed on the Highmont pit by constraining its extent to Teck’s mineral tenure claims, the Mineral Reserve pit was also constrained to preclude mining through Highmont Creek and the wetlands around it, to the west of the pit. The Valley pit was restricted at the Whittle phase to exclude mining within 100 m of the nearest paved shoulder of Highway 97, leaving a corridor for service roads and infrastructure. The resulting pit designs extend outside of the constraining Mineral Resource pit shells in multiple locations, particularly in the Highmont and Bethlehem pits, where the horizontal distance between the shells and the existing pit walls is insufficient for the mining equipment. For the mine plan and Mineral Reserves statement, all material outside of the Mineral Resource shells was converted to waste, regardless of confidence category.

The cut-off grades used for the Mineral Reserves statement were varied by pit and by period in the mine plan and were based on a strategy to maximize the net present value of the plan. Although expressed as a copper-equivalent grade, each pit was assigned a different cut-off to reflect differences in metal recoveries, milling costs, and haulage costs. Ore loss and dilution factors were not modelled. Internal dilution is inherent in using large mining blocks (approximately 25,000 t). At the time of extraction, the use of ShovelSense (a shovel-based sensor technology currently used to classify material as ore or waste as it is being loaded onto trucks) and smaller modeled blocks (approximately 4,000 t) with grades informed by blasthole samples is expected to minimize loss and dilution.

The Mineral Reserves include some material that was mined from the Valley open pit that was stockpiled from 2019–2024 on the top lift of the otherwise inactive Jurassic waste rock storage facility (WRSF), to the north of the Valley pit. This tonnage is scheduled to be processed by the mill in 2028. In the mine plan, some material will be stockpiled on the Valley North WRSF from 2035–2043 and is scheduled in the mine plan to be milled in 2046, the final year of the LOM.

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Mineral Reserves are reported at the point of delivery to the mill using the 2014 CIM Definition Standards. The estimate has an effective date of 1 July, 2025. The Qualified Person for the estimate is Mr. Tim Tsuji, P.Eng., a Teck Highland Valley Copper Partnership employee.

Mineral Reserves are summarized in Table ‎1-3.

Factors that may affect the Mineral Reserve estimates include: metal price and exchange rate assumptions; changes to the assumptions used to generate the cut-off grade, copper-equivalent grade, and molybdenum factor; changes in local interpretations of mineralization geometry and continuity of mineralized zones; changes to geological and mineralization shapes, and geological and grade continuity assumptions; density and domain assignments; changes to geotechnical assumptions including pit slope angles; changes to hydrological and hydrogeological assumptions; changes to mining and metallurgical recovery assumptions; changes to the input and design parameter assumptions that pertain to the open pit shell constraining the estimates; and assumptions as to the continued ability to access the site, retain mineral and surface rights titles, maintain environment and other regulatory permits, and maintain the social license to operate.

The LOM plan is based on conventional open pit operations using truck-and-shovel technology. The mine plan consists of the completion of the currently-active phases of the Lornex and Valley open pit designs, mining of the permitted but inactive Bethlehem open pit (including the historic Jersey and Iona open pits), a reactivation and extension of the Highmont pit, and an additional pushback of the Valley open pit.

A number of geotechnical studies were completed from 2015–2023 in support of mine designs. The geotechnical pit slope designs for the Valley, Lornex, Highmont, and Bethlehem pits were commissioned from Piteau Associates Engineering Ltd. The designs incorporated field investigations, data reviews, analyses, and plan updates.

Pit slope stability is regularly monitored at the Valley, Lornex, and Highmont pits. Bethlehem is not currently monitored due to inactivity.

Surface water from rainfall and snowmelt, and local seepage is currently captured by perimeter collection ditches and in-pit sumps in the active pits and collected for use in processing.

Selective extraction with shovels segregates ore from waste rock for processing. Conventional or autonomous haul vehicles transport the ore to crushers placed in or adjacent to the actively mined pits. Conveyor systems collect the crushed ore and transfer the ore to the Highland mill. Shovels load the segregated waste rock onto conventional or autonomous haul vehicles for transport and placement onto WRSFs along the perimeter of the active pits. All haul roads were designed in compliance with British Columbia’s Mines Act.

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Table ‎1-3:      Mineral Reserves Summary Table

Notes to Accompany the Mineral Reserves Table: 

At the Report effective date, there were 19 WRSFs in the Project area, nine of which are currently active. The predominant waste rock types are granite, granodiorite, quartz monzonite, and quartz diorite. When designing WRSFs, each dump lift is designed at the angle of repose (36–37º). The overall design dimensions consider long-term reclamation of the dump to the reduced maximum slope angle of up to 24º, which is less erosion prone and has been demonstrated to support revegetation that further stabilizes the reclamation covers.

The remaining mine life is approximately 21 years, ending in 2046 and will be followed by reclamation activities. About 2,581 Mt will be mined from the pits and approximately 3 Mt will be re-handled from the existing long-term stockpile. A total of about 1,102 Mt will be processed by the mill, including approximately 1,073 Mt that will be hauled directly from the pits to the primary crushers, the existing stockpile, and about 26 Mt of Valley ore stockpiled in future years and delivered to the crushers in 2046. About 1,752 Mt of waste rock and overburden will be mined, consisting mostly of in-situ material but also large, planned quantities in existing and future waste rock buttresses in the Valley pit and existing WRSFs in the Valley and Bethlehem pits. These quantities do not include smaller quantities of rehandled material anticipated as a part of routine operations.

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Drilling and blasting requirements for both current operations and the LOM plan are estimated on a bench-by-bench basis using parameters associated with current operational practice. This includes trim and buffer blasting along the perimeter of final walls and drill hole spacing determined by pit and material classification.

Production equipment includes shovels, trucks, drills, front-end loaders, dozers, and graders.

The mill is based on a robust metallurgical flowsheet designed for optimum recovery with minimum operating costs. The flowsheet is based upon unit operations that are well proven in industry. The mill operates 24 hours per day, 365 days per year. The processing circuit consists of crushers to size feed, overland conveyors to transfer feed, and milling facilities to produce the concentrate product.

The LOM plan assumes an increase in overall mill throughput, and the addition and modification of equipment within the existing mill. Modifications and changes are planned to include:

Ore from the pits will be hauled to one of three in-pit gyratory crushers. After crushing to the desired size, the material will be fed to overland conveyors, which distribute ore to three coarse ore stockpiles. These three stockpiles feed the five grinding circuits, lines A, B, C, D, and E.

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Currently, grinding lines A, B, and C each consist of a SAG mill for primary grinding and a pair of ball mills for secondary grinding arranged in a parallel configuration, with each ball mill in closed circuit with a cyclone cluster. The cyclone overflow from each secondary grinding circuit reports to the bulk flotation circuit. Equipment in grinding lines A, B and C will remain as per the current operation. However, as part of the initial modifications, lines A, B and C secondary grinding cyclone overflow will be combined and rerouted to feed a new ball mill circuit with a 12.0 MW C3 tertiary mill in closed circuit with a cyclone cluster. The C3 cyclone overflow will report to the bulk flotation circuit. Currently, grinding lines D and E each consist of an autogenous grinding (AG) mill for primary grinding. Pebbles generated in the autogenous grinding mills are conveyed to a separate pebble crushing building that contains two pebble crushers in parallel. Crushed pebbles are returned to the autogenous grinding mills for further grinding. Products from the two autogenous grinding mills are split between three ball mills operating in parallel (D/E/D3). Each ball mill is in closed circuit with a cyclone cluster. The cyclone cluster from each secondary grinding circuit currently reports to the bulk flotation circuit. Equipment in grinding line E will remain as per the current operation. However, as part of the initial modifications, the existing D-line autogenous grinding mill will be converted to a 10.5 MW SAG mill. The D and E primary mill products will continue to be fed to the existing D, E, and D3 ball mills, with ball mill cyclone overflow products reporting to the bulk flotation stage.

Currently, there are three rows of rougher/scavenger bulk flotation cells, where the rougher 1 concentrate from each line reports to a pair of high-grade columns. Rougher 2 and 3 concentrate from each line reports to two rows of recleaner cells. The scavenger concentrate reports to six low-grade cleaners. The existing flotation and regrind circuits will require some additions and modifications. The flotation cleaner circuits will be reconfigured and operate where there are still three rows of rougher/scavenger bulk flotation cells, where the rougher 1 concentrate from each line continues to report to a pair of high-grade columns. Rougher 2 and 3 concentrate from each line will be split, and will report to either the high-grade cleaners or the recleaners. The recleaners will be repurposed to perform the same function as the high-grade cleaners. The scavengers will report to the regrind circuit, which will contain an additional regrind mill.

In the high-grade columns, the concentrate will form part of the final bulk concentrate, while the tailings will report to the regrind circuit. In the high-grade cleaners and recleaners, the concentrate will report to the high-grade columns, while the tailings will report to the regrind circuit. The regrind circuit discharge will report to the existing low-grade cleaners. In the low-grade cleaners, the concentrate will feed the two existing low-grade columns, while the tailings will report to the scavenger tailings pump box during normal operation (with the option of recycling back to the rougher/scavenger flotation feed). In the low-grade columns, the concentrate will form part of the final bulk concentrate, while the tailings will return to the low-grade cleaner cells.

The nominal mill combined feed to the rougher flotation circuit from all grinding lines will be about 7,058 t/h. The existing rougher flotation circuit consists of three lines, the existing distributor directing approximately 2,353 t/h solids to each line. Feed to the rougher flotation circuit will have a solids content of approximately 35% by weight and an 80% passing particle size of approximately 278 µm to all flotation lines. Feed copper grade to each line is about 0.3% Cu and each line will have an overall mass recovery of approximately 4.0%. All three lines are configured as seven 300 m3 forced-air tank cells with the first three cells of each row functioning as rougher cells and the remaining four as scavenger cells. Line 1 has its own R1, R2, and R3, and scavenger concentrate pump boxes, while lines 2 and 3 share R1, R2, and R3, and scavenger concentrate pump boxes for transport. All the scavenger cells either have been or will be modified to add froth crowders and center launders. The upgrade is currently in progress. 

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The existing high-grade column feed pump box will receive R1 concentrate from all three rougher flotation lines as well as concentrate generated in the high-grade cleaner and recleaner circuits. A new bypass from line 1 R2 and R3 concentrate will also feed this circuit. The existing circuit directs high-grade cleaner tailings to the low-grade cleaner cells, which then feed the regrind circuit. This flow path will be modified to direct high-grade cleaner tailings to regrind, which will then feed low-grade cleaners.

To accommodate the increased regrind circuit feed rate, the regrind circuit will be modified by the addition of a new 500 kW IsaMill M1000 to accept feed in parallel with the existing regrind mill. Each mill will process 52 t/h (regrind cyclone underflow). The mills will operate in open circuit with the cyclones whereby feed is pumped to the cyclones, the cyclone underflow is directed to both mills, and mill discharge is combined with cyclone overflow as final product.

The existing low-grade cleaner flotation circuit consists of a single line of six 100 m3 tank cells. The low-grade cleaner circuit will operate such that 25% of the feed mass will be recovered in the concentrate, with an overall copper recovery of approximately 90%. To accommodate the new throughput, a centre launder and froth crowder will be added to all six low-grade cleaner cells.

The existing low-grade column flotation circuit consists of two 3.05 m diameter by 8 m high column cells configured in parallel. A distributor accepts concentrate feed from the low-grade cleaner cells. Feed from the low-grade column distributor is directed equally to column cells 1 and 2 at a solids content of approximately 31% by weight. Column 2 can also accept feed from both of the high-grade column distributors.

The copper and molybdenum concentrates are filtered, dewatered, and stockpiled before being transported to domestic and overseas markets. The tailings waste generated from the flotation processes is pumped to the Highland TSF.

Reagents and consumables used in the mill include, and will continue to include: Unidri (defoamer), carbon dioxide (pH modifier), caustic soda (caustic scrubbers), chlorine (regenerate ferric chloride for leaching), Polyfroth W31 (frother), fuel oil (molybdenum collector), hydrochloric acid (regenerate ferric chloride for leaching), lime (pH modifier), nitrogen (liquid) (flotation), pine oil (frother), potassium amyl xanthate (collector), sodium hydrosulphide (copper depressant), sodium isopropyl xanthate (collector), IPAC 1249A (Scale Inhibitor), AERO 7260 (copper depressant), Molycop 1" (copper cementation) and grinding media.

The majority of make-up water required for the Highland mill will be acquired from the Highland TSF reclaim system (i.e., ponded water). Water is expected to be recycled back to the mill at a rate of 12,500 m3/h for reuse in the processing circuits.

Power to the operation is provided by a BC Hydro 138-kilovolt (kV) line that connects to the site grid at three substations.

Existing infrastructure includes:

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The LOM plan will require:

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There are four major TSFs; three of which, Highmont, Bethlehem, and Trojan, are closed and reclaimed. The currently active primary TSF is the Highland TSF. Two auxiliary TSFs, the 7-Day Pond TSF and 24 Mile TSF, are also active. The 7-Day Pond TSF, located adjacent to the Highland mill, and 24 Mile TSF located downstream of the H-H dam, are classified as TSFs and receive minor amounts of tailings from the mill during upset conditions.

At the Report effective date, the Highland TSF dam(s) were permitted for raises up to elevations of 1,310 m nominal for the L-L dam, and 1,326 m nominal for the H-H dam. Raises to current crest elevations are needed to accommodate about one billion tonnes of additional tailings that will be generated by the LOM plan.

A site-wide operational water balance model is used for managing water for the mining and milling operations. The mine uses approximately 109 Mm3 of water annually (approximately 82 Mm3 of which is reused). Water is recycled from the TSF pond via barge pumps to a booster pump station that pumps water to a reservoir approximately 150 m of elevation above the pond surface. The water then flows by gravity to the mill for use in processing. The process make-up water (approximately 27 Mm3 per annum) is currently supplied from a combination of surface runoff inflows, seepage inflows, and groundwater wells to replace losses primarily from evaporation on the TSF surface and entrainment in tailings. The site water supply strategy will not change through the LOM, although the increase in throughput will require an increase in make-up water supply due to the additional water losses to tailings voids. It is expected that 272 m3/h or approximately 2.4 Mm3 of additional make-up water will be required over the current average LOM requirements. This water is planned to be sourced from depressurization wells in the Valley pit.

Modifications to the Highland TSF water reclaim system are required to increase the system capacity for higher mill throughputs and to accommodate the higher ultimate TSF tailings and water elevations resulting from the LOM plan. Expansion of the L-L dam will encroach on the existing sediment, seepage, and surface water management infrastructure located at the toe of the dam and replacement facilities will be required. The Woods Creek diversion will require relocation in 2029 to continue operation throughout the LOM. No new diversions are required for the H-H dam. The 24 Mile TSF will be fully capped by WRSFs during the LOM and an alternative storage pond for overflow tailings from the tailings booster pumphouse is planned.

Teck manages an inventory of local lakes and reservoirs that form an integral part of the non-contact (e.g., fresh water) and contact water (e.g., process water) management system on site. These lakes and reservoirs are contained by constructed dams and abutment structures ranging from approximately 3–22 m in height.

The mine does not operate a camp or accommodation system; all employees are housed off-site. Due to the proximity of nearby communities and their relative population, all mine employees are expected to find suitable accommodation with personal access along Provincial Highway 97C to the mine site. Employees typically reside in Kamloops, Logan Lake, Merritt, Ashcroft, or smaller communities near the mine site.

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Electrical power to the mine is currently provided by a single 138 kV transmission line. The transmission line runs from BC Hydro’s Nicola Substation to the operations with connection points at three Teck-owned substations: Highmont substation adjacent to the mill, L-L substation at the L-L dam, and Spatsum substation at the Spatsum pumphouse on the Thompson River.

The operations currently have the power supply required. The current power demand is approximately 128.1 MVA (design). The LOM will require 170.9 MVA (design), with the four largest additional draws being the C3 mill (14.7 MVA), mining equipment additions (6.9 MVA), mining and dredging at Bethlehem (6.0 MVA) and additional loads for the AG and SAG mills (5.4 MVA). To meet the additional power demand, upgrades are planned at the Nicola substation and on a segment of the transmission line.

Teck’s market research team performs market studies for the metals and concentrates that Teck produces from the Highland Valley Copper Operations. Copper and molybdenum supply and demand forecasts were completed.

Key considerations regarding the copper concentrate marketability include:

The copper grade in concentrate will average approximately 35% over the LOM, which classifies it as a high-grade product.

Teck currently sells its molybdenum concentrate production in the custom roasting market as molybdenum concentrates. The market for custom molybdenum concentrates outside of China is split almost equally between three major firms, with a couple of smaller players. There are no forecast significant changes to the molybdenum concentrate quality and the sales of future molybdenum concentrate from the Highland Valley Operations are expected to continue to be made into the custom-roasting market.

Teck has implemented a standardized approach for commodity price and exchange rates to be used in estimating Mineral Resources and Mineral Reserves, and in the cashflow analyses that support the Mineral Reserves. The LOM forecasts are US$3.80/lb Cu, US$15.20/lb Mo, and a US:CAD exchange rate forecast of 1:1.31.

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Teck currently has entered into spot, medium- and long-term contracts with international shipping companies to deliver Highland Valley Copper concentrates sold under sales agreements with customers. The future contract approach will continue to have a set of spot, medium- and long-term contracts with a diverse set of customers, all of which will be managed by Teck.

Teck has contracts in place with third-parties that provide services, supplies, and construction services to the site. These contracts include mining services and supplies required for the operation such as explosives, reagents, and contract maintenance activities. Contracts are managed by Highland Valley Copper’s supply chain department and are expected to be renewed within industry norms for the LOM.

The existing operations currently operate under provincial Mines Act Permit M-11 (formerly Reclamation Permit M-11), first issued on 20 January, 1970. The permit has been amended over time to reflect the mine development and amalgamated separate provincial Mines Act Permits originally granted for the Bethlehem and Highmont operations.

The Environmental Assessment Certificate that supports the LOM was issued on 17 June, 2025. The associated M-11 permit amendment was issued on 18 June, 2025.

Teck has established environmental monitoring programs for the operations, which include comprehensive monitoring of the mine site, discharge locations, and the receiving environment. The existing environmental monitoring programs are intended to enable ongoing evaluation of environmental management performance and receiving environment conditions, with all monitoring activities coordinated and tracked. Long-term monitoring stations have been established for environmental monitoring programs and will be maintained throughout the LOM to facilitate long-term trend analysis. Monitoring programs are spatially comprehensive, and established sampling and QA/QC methods will continue to be used.

Teck submitted a comprehensive closure plan as part of the Environmental Assessment Certificate application that was approved 17 June, 2025. The plan must be updated and provided to the Chief Inspector at least every five years.

The Highland Valley Copper Operations also maintains an End Land Use Plan, which establishes end land use objectives, post-closure capability metrics and site-specific reclamation prescriptions to inform the reclamation and closure planning. The End Land Use Plan must be updated every 10 years and incorporated into reclamation and closure planning. The next update of the End Land Use Plan and the regulatory reclamation and closure plan must be completed and submitted in December 2026.

The reclamation liability cost estimate was last updated in 2024 as part of the Environmental Assessment Certificate application, resulting in a total estimated liability of $959 M. The reclamation liability cost estimate is updated and submitted annually as part of the site annual regulatory reporting, at least every five years in alignment with the submission of the regulatory reclamation and closure plan, and with every substantial Mines Act M-11 permit amendment application.

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Teck currently has approximately $351 M of bonding in place with the Ministry of Finance, and will be required to post an additional $368 M by 30 September 2025 to ensure that the closure cost estimate is fully bonded.

The Highland Valley Copper Operations received the provincial Mines Act Permit M-11 in 1970 and still operate under that permit, as amended. The operations also hold the additional permits, licences and authorizations required to construct, operate, and close the operations.

Teck understands that maintaining strong relationships with local Indigenous Governments and Organizations and other communities of interest is essential to facilitating responsible mining and generating economic benefits, advancing reconciliation efforts, and improving community well-being. Social management at the Highland Valley Copper Operations is guided by Teck’s Social Performance Standard.

In accordance with the Social Performance Standard, an annual review and mapping of communities of interest and social risks informs the development of a Social Management Plan that guides annual site-level strategies and plans for community engagement and social impact management.

Teck recognizes that respecting the rights, cultures, interests, and aspirations of Indigenous people is fundamental to the operation and to meeting the company’s commitment to responsible resource development. As such, Teck, via its subsidiary Teck Highland Valley Copper Partnership, has established formal agreements with Nlaka’pamux Governments and Organizations as well as the Stk'emlupsemc te Secwepemc Nation. The agreements are intended to provide the foundation for long-term, mutually beneficial relationships and a framework for communication, collaboration, and cooperation in areas such as employment, contracting and procurement, environmental management, regulatory matters, cultural heritage management, closure, and economic benefits.

In accordance with these agreements, Highland Valley Copper Operations staff and representatives from Indigenous Governments and Organizations align on annual priorities and objectives in areas respective to each agreement and hold regular agreement implementation committee and technical working group meetings. A condition of the provincial M-11 Mines Act permit includes the establishment and maintenance of a Nlaka’pamux Implementation Board that includes Nlaka’pamux representatives to provide advice on environmental management, monitoring, reclamation, and closure activities of the Highland Valley Copper Operations.

Teck’s Community Investment Program provides opportunities for investments in organizations and initiatives that create shared value, support sustainable development, and focus on shared strategic outcomes that help advance the achievement of the United Nations’ Sustainable Development Goals.

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Capital cost forecasts are based on a 21-year mine life, from 2025–2046, with the first and last years being partial years. The estimated capital expenditures reflect funds to support operations, including funding for new and expanded facilities, infrastructure, equipment additions and replacements, and in-pit drilling.

Key elements for growth capital, which covers the initial expansion phase from 2025–2027 include:

Key elements for sustaining capital estimates include:

Capital cost estimates for the LOM are summarized in Table ‎1-4 and total approximately $4,275 M.

Operating cost forecasts are based on a 21-year mine life, from 2025–2046, with the first and last years being partial years. Operating costs include the mine, mill and administration costs related to site production and do not include off-site costs such as marketing and freight. Cost estimates are based on actual site operating cost history and budgetary estimates. Key cost inputs include:

Operating cost estimates for the LOM are summarized in Table ‎1-5 and total approximately $19,062 M. The unit operating cost estimate for the LOM averages $17.32/t milled.

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Table ‎1-4:     Capital Cost Estimate Summary Table (C$M, nominal terms)

Note: all numbers have been rounded.

Table ‎1-5:     Operating Cost Estimate Summary Table (C$M, nominal terms)

Note: all numbers have been rounded.

Teck is relying on the exemption whereby producing issuers may exclude the information required under Item 22 for technical reports on properties currently in production and where no material production expansion is planned.

Mineral Reserve declaration is supported by overall site positive cash flows and net present value assessments.

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The QPs reviewed the risks to the Mineral Resource and Mineral Reserve estimates, and summarized these in Sections 1.12 and 1.14, respectively. In addition to those risks, the potentially major risks to the mine plan and the economic analysis that supports the Mineral Reserves include:

There is upside potential for the Mineral Reserve estimates if mineralization that is currently classified as Inferred can be upgraded to higher-confidence Mineral Resource categories and supports conversion to Mineral Reserves.

Mineralization in the Avalanche unit is currently scheduled as waste in the LOM plan. However, if additional testwork and supporting studies can demonstrate that the mill can treat mineralization with elevated oxide and clay contents, this mineralization may be able to be included in Mineral Resource and Mineral Reserve estimates, and subsequently incorporated into the LOM plan.

Improved equipment productivity and availability will increase efficiencies and potentially reduce unit operating costs.

Site optimization for the planned crusher relocation is underway. Depending on the site selected, there may be an opportunity to reduce operating and sustaining capital costs by decreasing truck requirements, or by replacing a portion of the haulage diesel with electric conveyors.

Under the assumptions in this Report, the Mineral Reserves declaration is supported by overall site positive cash flows and net present value assessments. The mine plan in the Report is achievable under the set of assumptions and parameters used.

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As the Highland Valley Copper Operations are in production, studies to support the LOM plan have concluded, and the Environmental Assessment Certificate and modifications to the M-11 permit have been granted, the QPs have no material recommendations to make.

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2              INTRODUCTION

Mr. Christopher Hercun, P.Eng., Mr. Alex Stewart, P.Geo., Mr. Tim Tsuji, P.Eng., Mr. Frank Laroche, P.Eng., and Mr. Carl Diederichs, P.Eng. prepared this technical report (the Report) for Teck Resources Limited (Teck) on the wholly-owned Highland Valley Copper Operations (Highland Valley Copper or the Project), located in British Columbia, Canada (Figure ‎2-1, 2-2).

Teck uses a subsidiary, Teck Highland Valley Copper Partnership (Highland Valley Copper Partnership), as the operating entity for the Highland Valley Copper Operations.

The Report was prepared to support Teck’s news release dated 23 July 2025, entitled “Teck Announces Construction of Highland Valley Copper Mine Life Extension to Proceed”.

Teck commenced the permitting application process for the life-of-mine (LOM) plan described in this Report in 2019. The initial application referred to the mine plan as the Highland Valley Copper 2040 Project (HVC 2040), later changing to the HVC Mine Life Extension Project (HVC MLE). The permits were granted in 2025, and the permitted mine life extension project is the LOM plan in this Report.

Mineral Resources and Mineral Reserves are estimated for the Valley, Lornex, Highmont, and Bethlehem deposits.

Mineral Resources and Mineral Reserves are reported using the confidence categories in the Canadian Institute of Mining, Metallurgy and Petroleum (CIM) Definition Standards for Mineral Resources and Mineral Reserves (May 2014; the 2014 CIM Definition Standards).

The Mineral Resource and Mineral Reserve estimates are forward-looking information and actual results may vary. The risks regarding Mineral Resources and Mineral Reserves are summarized in the Report (see Section 14, Section 15, and Section 25). The assumptions used in the Mineral Resource estimates are summarized in the footnotes of the Mineral Resources table and outlined in Section 14 of the Report. The assumptions used in the Mineral Reserve estimates are summarized in the footnotes of the Mineral Reserves table and outlined in Section 15 and Section 16 of the Report.

Units presented are typically metric units, such as metric tonnes, unless otherwise noted.

The Report uses Canadian English.

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Figure ‎2-1:     Project Location, Provincial

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Figure ‎2-2:     Project Location, Regional

Currency is expressed in Canadian dollars (C$) unless stated otherwise.

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This Report has been prepared by the following Qualified Persons (QPs):

Mr. Hercun has been a Teck employee since 2010 and has worked at the Highland Valley Copper Operations since 2013. While at the operations, he has routinely visited and inspected core drilling operations, core handling processes, the open pit workings, verified regulatory permitting, and visited key site infrastructure. He also participated in technical studies, planning, and economic evaluations related to the LOM plan and mine life extension studies.

Mr. Alex Stewart has been a Teck employee since 2011, working at the Highland Valley Copper operations throughout his tenure. He has been involved in Mineral Resource estimation since 2012. While on site he has visited and inspected the open pit workings, reviewed drilling operations, core logging, sampling procedures, shipping practices and core storage facility. He also reviewed and discussed geological interpretations and estimation practices with the geology group.

Mr. Tim Tsuji has been a Teck employee since 2012 and has worked at the Highland Valley Copper Operations as a long-term mine planner throughout his tenure. He has visited the open pit workings and revises their designs in response to changes in the resource models and economic, geotechnical, and operational conditions. He has been involved in Mineral Reserve and Mineral Resource estimation for the site since 2014.

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Mr. Laroche has been a Teck employee since 2008 and has worked at the Highland Valley Copper Operations for over 17 years. During his tenure, he has conducted site visits and inspected all of the current mineral processing stages, including the crushing, grinding, flotation, leaching and dewatering steps. He has provided contributions to geometallurgical programs through sample selection and performance analysis. He has direct involvement in copper recovery and throughput modeling, and familiar with the design and ongoing reconciliation process.

Mr. Diederichs has been a Teck employee since 2008 and worked at the Highland Valley Copper Operations from 2008–2010, and from 2012 onward. While at the operations he has routinely visited and inspected the open pits, tailings, and waste rock storage facilities, and led, participated in, and reviewed their associated geotechnical studies. He has direct involvement in the planning and operation of the open pits, tailings and waste rock storage facilities and is familiar with their design and ongoing management practices.

There are a number of effective dates pertinent to the Report, as follows:

The overall Report effective date is taken to be 1 July, 2025, and is based on the effective date of the Mineral Reserve estimates.

The reports and documents listed in Section 27 of this Report were used to support Report preparation.

Additional information was sought from Teck personnel where required.

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Teck has previously filed the following technical reports on the Project:

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3              RELIANCE ON OTHER EXPERTS

This section is not relevant to this Report.

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4              PROPERTY DESCRIPTION AND LOCATION

The Highland Valley Copper Operations are located approximately 75 km southwest of Kamloops British Columbia (BC) and 17 km west of the town of Logan Lake, BC. The centroid of the operations is situated at latitude 50° 28ʹ 27ʺ N and longitude 121° 01ʹ 15ʺ W.

The operations are wholly-owned by Teck Resources Limited. Teck uses a subsidiary company, Teck Highland Valley Copper Partnership, as the operating entity.

The mineral tenure area consists of 941 active mineral claims (55,625 ha), 106 active mining leases (3,391.1 ha) and 18 active Crown grants (private mineral holdings; 1,237.9 ha) that collectively cover about 60,254 ha. A complete list of the tenures, with their grant and expiry dates and areas, is provided in Appendix A. An overview map showing the tenure is provided in Figure ‎4-1. Detailed tenure maps are included in Appendix A.

All tenure is held 100% in the name of the Teck subsidiary Teck Highland Valley Copper Partnership.

The mineral claims and mining leases are renewed annually, per the BC Mineral Tenure Act. Crown grants are an interest in land as a fee simple estate in ownership. These rights are held in perpetuity by Highland Valley Copper Partnership if the assessed property and mineral taxes are paid annually. All required payments were current at the Report effective date.

Surface rights in the Project general area are held by a number of different licence types (Table ‎4-1, Figure ‎4-2), all of which are 100% in the name of Teck Highland Valley Copper Partnership. A portion of the leases are land-based facility leases, which grant the holder the right to use the surface of the land for specific purposes outlined in the lease agreement.

Additional land acquisition may be required for easements to support the LOM plan. The following components may require additional land compared to the existing permitted area of operation:

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Figure ‎4-1:     Mineral Tenure Location Map

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Table ‎4-1:     Surface Rights Table

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Note. LBF lease = land-based facility lease; BC = British Columbia; N/A = not applicable.

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Figure ‎4-2:     Surface Land Holders

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Teck currently holds 26 active BC water licences in the name of the Teck Highland Valley Copper Partnership, which have expiry dates ranging from 2026–2053 (Table ‎4-2). Water licences are renewed as necessary per the BC Water Sustainability Act.

There are no royalties, back-in rights, payments or other agreements outside of the percentage distributions of the Teck Highland Valley Copper Partnership on claims held to cover the Highmont, Valley and Lornex open pits.

Permitting for the Highland Valley Copper Operations is discussed in Section 20.

Environmental considerations and monitoring programs for the Highland Valley Operations are discussed in Section 20.

There are environmental liabilities associated with the mining and processing activities. In order to minimize these environmental liabilities, Teck has secured all required environmental permits and conducts work in compliance with these permits. Additionally, Teck endeavors to comply with all applicable legal and other obligations.

Social considerations for the Highland Valley Copper Operations are discussed in Section 20.

To the extent known to the QPs, there are no other significant factors and risks that may affect access, title, or the right or ability to perform work on the Project that are not discussed in this Report.

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Table ‎4-2:     BC Water Licences

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5              ACCESSIBILITY, CLIMATE, LOCAL RESOURCES, INFRASTRUCTURE AND PHYSIOGRAPHY

The operations are readily accessible by paved highway, including from Vancouver via Highway 1 to Highway 5 (the Coquihalla Highway) to Merritt, and then via Highway 97C to Logan Lake and the Highland Valley Copper Operations. Highway 97C also connects the site to Ashcroft, location of the railway terminal for copper concentrate handling.

No freight or passenger rail services are available directly from the site. The nearest freight rail services are at the Ashcroft terminal (access to both Canadian National (Canadian National) Railways and Canadian Pacific (Canadian Pacific) Railways with industrial transloading, materials handling, and industrial storage capabilities. Services offered at Ashcroft include bulk, break-bulk, and container (forthcoming) handling. Passenger rail services provided by VIA Rail and Canadian Pacific are available in Kamloops.

There are three airports within the Thompson–Nicola Regional District, one of which provides commercial services. The Kamloops Airport, serviced by Air Canada, West Jet, and Central Mountain Air, provides commercially scheduled and charter air transportation services for area residents and cargo to Vancouver, Calgary, and other western Canadian destinations. Non-commercial services are available at the Cache Creek/Ashcroft Airport and the Merritt Airport. The nearest international airport with commercial services is the Kelowna International Airport, located outside the Thompson–Nicola Regional District.

The climate is characterized as semi-arid, characterized by warm summers, cold winters, and the lack of a distinct wet season or dry season. Regional weather and climatic conditions are strongly influenced by elevation, slope aspect and proximity to Kamloops Lake and the Thompson River valley. Temperatures range from an average daily maximum of 21.2°C in the summer to an average daily minimum of -9.7°C in the winter. Extreme temperatures have reached a low of -43.9°C and a high of 35.0°C.

The mine site experiences a rain-shadow effect from the Pacific Coastal Mountains that are situated to the west. Precipitation occurs as both rain and snow, with a higher contribution from rainfall on an average annual basis. The Highland Valley area receives an average of 393 mm of precipitation annually, of which about 243 mm falls as rain. Convective storms are an important source of precipitation in the summer and average precipitation is generally highest in June. Winter precipitation in the form of snow is relatively low and accumulation varies with topography and elevation; snowfall is generally highest in December. Snow melt typically occurs in mid-April, initiating freshet.

Valley bottoms are arid, with potential evaporation substantially higher than precipitation.

The prevailing wind direction in the Highland Valley is from west to east, particularly in the summer months.

Mining operations are conducted year-round.

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Infrastructure that supports the current operations is in place (see also discussions in Section 16, Section 17, and Section 18 of this Report). These Report sections also discuss water sources, electricity, personnel, and supplies for the LOM plan.

The nearest communities to the mining operation are Logan Lake (17 km), Ashcroft/Cache Creek (34 km), Merritt (60 km), and Kamloops (75 km).

The mine is located within the approximately 23 km long Highland Valley, at the lower elevation end of the Thompson Plateau in the southern Interior Plateau region of BC, on the eastern slope of the Pacific Coastal Mountains.

Multiple glaciations and subsequent erosion and deposition of post-glacial streams shaped the Highland Valley, and bedrock structural features mainly control its topography. Glacial and post-glacial deposits cover more than 90% of the bedrock. The western part of the Highland Valley exhibits distinct hanging valley features, while the axis of its eastern part narrows into a bedrock canyon.

The Highland Valley is bounded on the west by the Thompson River, and on the east by the Guichon Creek Valley.

The region is characterized as having hummocky terrain with gentle (5%) to moderate (50%) slopes. The elevation in the valley ranges from 1,000–1,850 metres above sea level (masl). The Project area ranges in elevation from 1,000–1,750 masl with the highest elevations occurring in the southwestern part of the area. The mining operations are situated at approximately 1,280 masl.

The mining operations are within the Thompson Basin and Guichon Upland Ecosections of the Thompson–Okanagan Plateau Ecoregion. Species vary depending on moisture availability, elevation, and aspect, and typically consist of fire-dominated, dry-land vegetation. Key species in the Project area include:

Changes to vegetation and ecosystems in the Highland Valley have occurred over time because of both natural (e.g., forest succession, fires, climate change) and anthropogenic (e.g., agriculture, forestry, mining, recreational development) forces and activities.

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The Project area is included in the General Resource Management Zone defined under the Kamloops Land and Resource Management Plan, within which mineral development is identified as an allowable land use. The Kamloops Land and Resource Management Plan outlines objectives and strategies for mineral development that provides for local employment and investment, and for maintaining or enhancing land access for mineral exploration and development. The Kamloops Land and Resource Management Plan specifically identifies Highland Valley Copper as a large, producing metal mine in the region.

The Thompson–Nicola Regional District has a history of development and land use that includes forestry, ranching, and mining dating back to the early 1900s. It currently supports substantial urban settlement, mining, forestry, agriculture, recreation, and transportation including several highway and railway corridors.

The lands surrounding the operations primarily consist of forest and grassland ecosystems, which are used by Indigenous peoples for economic, cultural, and spiritual purposes. In addition, the region supports various land uses such as parks and protected areas, recreational activities such as trails, hunting, and fishing, as well as forestry and agricultural practices, including ranching and rangeland.

There are no provincially designated parks or protected areas within, or overlapping, the mine site, although there are seven provincial parks within 25 km of the operations.

The mine site is located within the Kamloops timber supply area and overlaps 40 active or pending cut blocks. Teck holds 31 of these, and nine intersect with forest licenses held by private entities.

The operations are surrounded by cattle ranching, with five crown land range tenures adjacent to the mine.

The Highland Valley is a significant area for Indigenous Peoples who have historically occupied the area and continue to use it today; primary and traditional uses include but are not limited to: hunting, fishing, gathering, other cultural and spiritual purposes, agriculture, and livestock watering. The Highland Valley Copper Operations are located within the unceded territory of the Nlaka’pamux Nation, and the Secwépemc Nation also have interests in the area.

Seismic assessments suggest that seismic hazards for the operations can come from three sources, shallow crustal earthquakes, great subduction-interface earthquakes, and deep in-slab earthquakes. The local crustal earthquakes are the most likely in southern BC.

A deterministic seismic hazard assessment completed in 2018 indicated low predicted peak ground accelerations in the vicinity of the main mine infrastructure.

Surface rights for the current operations are in place.

Additional land acquisition for easements may be required to support the LOM plan (see Section 4.4).

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6              HISTORY

The exploration and development history is outlined in Table ‎6-1.

Mining began in 1962 at the Bethlehem Copper operation. Three open pits (Huestis, Jersey, and Iona) and two TSFs, the Bethlehem and Trojan TSFs, were developed during the Bethlehem Copper operation and were used until 1982. In 2019, Teck received an amendment to the M-11 Mines Act permit to allow for additional mining from the Jersey and Iona pits, but as of the Report effective date, none of the Huestis, Jersey, and Iona pits or the Bethlehem and Trojan TSFs were active.

In 1972, the Lornex Mining Corporation started production, developing the Lornex open pit and constructing the Highland mill and TSF, all of which continue at the Report effective date.

Highmont Mining Corporation operated from 1980–1984, developing the Highmont East pit, the Highmont West pit, the Highmont mill and the Highmont TSF. Mining recommenced in 2005 from the Highmont East pit, and re-purposed the Highmont West pit as a WRSF. The Highmont TSF is inactive at the Report effective date.

Cominco (now Teck) acquired Bethlehem Copper in 1980 to consolidate its holdings in the area, which were centered on the Valley deposit, and started production from the Valley pit in 1983. The Bethlehem mill processed ore from the Valley pit until 1986, when the Highland Valley Copper Partnership was formed between Cominco and Lornex, and the Highland (Lornex) mill began processing Valley ore. In 1987, Highmont was added to the Highland Valley Copper Partnership and in 1989 the Highmont mill was moved to its current location, adjacent to the Highland mill. In 2014, the Highland Valley Copper Partnership completed a large mill optimization program centred around a new, modern flotation complex.

In 2018, Teck formally began permitting activities for the Highland Valley Copper Operations mine life extension with the Province of British Columbia, to extend operations to 2040 or beyond by mining additional material from the Highmont and Valley pits and increasing the capacity of the Highland TSF. The permit was granted on 17 June, 2025 (see Section 20.1).

The locations of the current and former open pits are provided in Figure ‎6-1.

The production history is provided in Table ‎6-2. Reliable production information is not available prior to the Highland Valley Copper Partnership merger in 1986; thus the table only provides verifiable production data from 1986 onwards.

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Table ‎6-1:     Ownership, Exploration and Development History

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Figure ‎6-1:     Location Plan, Current and Former Open Pits

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Table ‎6-2:     Production Table

Note: n/a = not applicable. No reliable production data is available prior to 1986. 2025 production data is a partial year, from 1 January 2025 to 30 June, 2025.

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7              GEOLOGICAL SETTING AND MINERALIZATION

The Project is situated within the allochthonous Quesnel Island Arc Terrane of the southeastern Intermontane Belt. Intrusions belonging to the Lower Jurassic Guichon Suite are a major component of the Quesnel terrane, extending over a surface area of more than 1,000 km2. Plutonism migrated from west to east during the formation of the upper Triassic to lower Jurassic Nicola Group, with the Guichon Creek Batholith representing the oldest (~210 Ma), and westernmost intrusion belt of the Quesnel terrane.

The intrusive rocks are spatially related to the volcano–sedimentary units of the Nicola Group. Major lithologies within the Nicola Group include calc-alkaline andesite, dacite, and rhyolite flows and ignimbrites, with relatively alkaline augite porphyry flows, analcite trachybasalt and trachyandesites, and minor limestones, shale, and quartzite.

Rapid uplift and erosion of the batholith resulted in formation of Jurassic sedimentary basins along the north and northwest margins of the batholith. Rocks of the basin-fill Ashcroft Formation consist of argillite, siltstone, sandstone, conglomerate, and minor limestone. Overlying the Jurassic rocks along the southwest flank of the batholith are mid-Cretaceous volcanic units of the Spences Bridge Group comprising mafic to felsic lavas, and volcaniclastic and interbedded epiclastic rocks. Tertiary continental volcanic and sediments cover extensive areas of the batholith, overlying earlier units from north of Highland Valley to the Thompson River.

Recent glacial-derived deposits overlie all lithologies.

A regional geology plan is included as Figure ‎7-1.

In the vicinity of the Guichon Creek Batholith in the Highland Valley, the Nicola Group is primarily volcanic in composition on the northern and eastern rim of the batholith, consisting of basalts and basaltic andesites, with locally abundant breccias and agglomerates. Sedimentary rocks are more common on the southern and western batholith margins, and comprise chert, siltstone, sandstone, greywacke, limestone, and volcanic conglomerate which grades to sedimentary volcanic breccia.

The Guichon Creek Batholith extends over an approximate area of 60 x 30 km. It is a is a north–northwest elongated multi-phase intrusion with major compositional variations that evolve from an older mafic margin inward to a younger and generally more felsic core (Table ‎7-1).

Contacts between the phases, though locally sharp, are commonly gradational and define an annular zoning with the older phases towards the outer margins of the batholith and the younger phases within the central area. The phases are nearly concentric in plan view.

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Note: Figure from Ryan et al., (2020). CC: Cache Creek ; QN: Quesnel; ST: Stikine; SM: Slide Mountain.

Figure ‎7-1:         Regional Geology Map

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Table ‎7-1:        Key Phases, Guichon Creek Batholith

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Numerous syn- to post-mineralization porphyritic to aplitic dykes and stocks cut the main intrusive facies with the highest density occurring primarily within and adjacent to the porphyry deposits. The most significant of the dykes are the northwesterly-striking Gnawed Mountain dyke that is associated with mineralization at the Highmont deposit, and a northerly-striking dyke swarm that extends from the Skuhun Creek fault through the Highland Valley to the Barnes Creek fault.

The porphyry deposits are hosted either in younger phase rocks, or in dyke swarms and intrusive breccias associated with the younger phase rocks.

A project-wide geology map is provided in Figure ‎7-2.

The batholith is elongated northward and segmented by major north- and northwest–west-striking faults that are closely related to mineralization (refer to Figure ‎7-2). The major northerly-trending structures include the central Lornex fault, the bounding Guichon Creek fault to the east, and the Western Boundary Fault to the west. Northwesterly-trending structures include the Skuhun Creek, Highland Valley, and Barnes Creek faults.

Dykes appear to preferentially occupy large-scale tension fractures that have similar orientations to the major fault directions.

Adjacent to the batholith contact, a metamorphic halo up to 500 m wide developed. Close to the batholith contact, assemblages are typical of the hornblende hornfels facies, further out, albite–epidote facies are typical.

Hydrothermal alteration of the Highland Valley deposits was generated by multiple generations of magmatic-hydrothermal fluid originating with the causative intrusion at depth.

Distal alteration includes green sericite, epidote, and chlorite, as veins and as fracture coatings. The type of vein alteration developed can reflect host rock composition; green sericite veins characterise the more felsic Bethlehem, Skeena, and Bethsaida phases, but chlorite (epidote) veins are more common in the earlier, more mafic batholith phases. Moderately to strongly developed distal alteration zones surround each of the five main deposits.

Proximal alteration and veining types include a barren core of intense quartz veining, potassic (potassic feldspar and hydrothermal biotite) and muscovite dominant. These are overprinted by late, structurally controlled sericitic and argillic alteration.

The major deposits are in the centre of the batholith, and include the Valley, Lornex, Highmont, Bethlehem, and JA deposits (refer to Figure ‎7-2). All the deposits except the JA deposit have been or are being mined; JA remains undeveloped.

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Note: Figure from Ryan et al., (2020).

Figure ‎7-2:         Deposit Area Geology Plan

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Significant copper mineralization occurred in several stages. The oldest followed the emplacement of Bethlehem granodiorite subfaces and coincided with dyke intrusion and breccia formation in the Bethlehem area; Bethlehem (and possibly the JA) is dated ca 209 Ma. The second phase, dated at ca 208 Ma, followed emplacement of the Skeena sub-facies and Bethsaida granodiorite sub-facies. The Valley, Lornex, Highmont systems formed at this time.

Most of the sulphide mineralization is developed in fractures, veins, faults, or breccia bodies. Higher grades typically occur where the fracture density is high or where several sets of fracture swarms overlap.

The first copper-mineralizing event followed the formation of the Bethlehem facies and occurred with the emplacement of porphyry dykes and breccias into these facies, forming the Bethlehem deposit. The second, and larger, copper–molybdenum mineralizing event followed the emplacement of the Bethsaida facies and resulted in the formation of the Valley–Lornex and Highmont deposits.

The originally contiguous Valley–Lornex deposit was cut by the late-stage Lornex fault, offsetting the Valley and Lornex deposits by about 3.5 km.

7.3.1.1            Deposit Dimensions

Chalcopyrite mineralization at the Valley deposit has a footprint of 2 x 1.5 km, which is elongate to the northwest. The deposit remains open at depth and has been drill tested to approximately 1,200 m depth.

7.3.1.2            Lithologies

The major lithologies are summarized in Table ‎7-2. A geology plan is provided in Figure ‎7-3, and an example cross-section in Figure ‎7-4.

Mineralization is hosted within the Bethsaida and Skeena phases of the Guichon Creek Batholith. The gradational northeast-dipping contact between these phases is preserved in the Lornex pit. In the Valley pit, this contact occurs to the north of the deposit. This difference in the location of the Bethsaida/Skeena contact relative to the mineralization in the Lornex and Valley pits is interpreted to be the result of a deeper level of erosion in the Valley area.

7.3.1.3            Structure

Three major fault systems cut the Valley–Lornex deposit (Table ‎7-3 and refer to Figure ‎7-3):

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Table ‎7-2:         Key Lithologies, Valley–Lornex Deposit

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Note: Figure from Ryan et al. (2020)

Figure ‎7-3:      Geology Map, Valley–Lornex Deposit

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Note: Figure from Ryan et al., (2020). Figure looks northwest.

Figure ‎7-4:         Cross-Section, Valley–Lornex Deposit

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Table ‎7-3:         Major Faults, Valley–Lornex Deposit

Mineralization is bound by the district-scale Lornex fault to the east in the Valley pit and to the west in the Lornex pit. Both the Lornex and Yellow fault systems display a primary control on the distribution of late sericitic and argillic alteration assemblages.

7.3.1.4            Alteration

Hydrothermal alteration in the Valley–Lornex deposit is characterized by a complex series of crosscutting veins and associated wall rock alteration that are classified into early-, main- and late stage types (Table ‎7-4). In plan view, footprints of the early- and main-stage alteration events are elongated along a west–northwest axis (Figure ‎7-5). Late-stage alteration is focused along north-trending structures and less commonly exhibits west–northwest orientations.

7.3.1.5            Mineralization

Copper and molybdenum mineralization is zoned around the centre of the deposit (refer to Figure ‎7-5), occurring as strongly, moderately, and weakly mineralized concentric halos around the barren core of high temperature quartz veins. Mineralization end abruptly to the east of the deposit centre at the Lornex fault. To the southwest of the deposit centre, an additional weak-to-moderate peripheral mineralized zone trends southwest to northeast. Alteration and mineralization styles suggest this is distal alteration controlled by the Yellow fault, which also trends southwest–northeast.

Sulphides zone from a bornite-rich centre outwards to a mixed zone of bornite–chalcopyrite, a chalcopyrite-dominant zone, and ultimately a peripheral zone where pyrite is more abundant. Late-stage veins associated with sericitic alteration locally overprint this concentric pattern and create narrow, 1–15 m wide, localized high-grade, coarse-grained chalcopyrite ± pyrite sulphide zones.

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Table ‎7-4:        Alteration Types, Valley–Lornex Deposit

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Note: Figure from Ryan et al., (2020).

Figure ‎7-5:        Alteration and Mineralization Map, Valley–Lornex Deposit

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Mineralization in the Valley deposit is strongly controlled by main-stage potassic–muscovite vein density, with most copper–iron sulphides occurring as vein fill or as coarse-grained disseminations/clots within coarse-grained muscovite vein halos. Chalcocite and lesser covellite occur locally as fine intergrowths within the central zone.

Molybdenite is concentrated in the outer portion of the potassic-muscovite domain and occurs as discrete vein and structurally controlled zones that crosscut main-stage alteration. Molybdenite typically occurs with quartz-carbonate veins, or as fine-grained fracture-coatings. Sulphide-rich crackle breccias can contain fine-grained molybdenite, however these are volumetrically-minor (generally <5 m thick and lack lateral continuity).

The argillic alteration event may also have introduced sulphides and has been observed to locally enrich main-stage mineralization where chalcocite–carbonate reaction rims have been observed on sulphide grains related to main-stage mineralization.

7.3.2.1            Deposit Dimensions

The chalcopyrite–bornite footprint of the Lornex deposit is about 2.2 km long by up to 1.5 km wide and is strongly elongated to the north–northwest. The deposit remains open at depth, to the southeast, and to the south. It has been drill tested to approximately 1,200 m depth.

7.3.2.2            Lithologies

The Lornex deposit is situated along the northwest-trending, steeply northeast-dipping contact between the Skeena and Bethsaida facies. The Bethsaida facies is restricted to the southwest part of the deposit, whereas the older and more mafic-mineral-rich Skeena facies is the predominant wall rock at Lornex.

A series of pre-, syn-, and post-mineralization dykes were emplaced within the central portion of the deposit and are flanked by the high-grade zones of mineralization. These intrusions make up the northwest extension of the Gnawed Mountain composite dyke.

The major lithologies are summarized in Table ‎7-5. The deposit geology was shown in Figure ‎7-3. An example cross-section is provided in Figure ‎7-6.

7.3.2.3            Structure

The major structures in the Lornex deposit area were illustrated in Figure ‎7-3.

The north-trending Lornex fault is surrounded by a 50–100 m-wide structural damage zone of low rock quality and multiple likely related fault planes. The Lornex fault dips steeply to the west and truncates mineralization in the west wall of the Lornex open pit.

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Table ‎7-5:        Key Lithologies, Lornex Deposit

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Note: Figure prepared by Teck 2025

Figure ‎7-6:       Cross-Section, Lornex Deposit

7.3.2.4            Alteration

Hydrothermal alteration in the Lornex deposit is also characterized by a complex series of crosscutting veins and associated wall rock alteration that are classified into early-, main- and late-stage types (Table ‎7-6). Alteration is similar to that of the Valley deposit previously described but with increased argillic and sericitic overprints leading to overall softer ore. The alteration system in the Valley–Lornex area was shown in Figure ‎7-5.

7.3.2.5            Mineralization

The mineralization zonation was shown in Figure ‎7-5.

Mineralization is dominantly vein and fracture-controlled, and to a lesser extent, disseminated in mafic mineral sites.

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Table ‎7-6:        Alteration Types, Lornex Deposit

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Bornite and chalcopyrite mineralization typically is hosted in planar, centimetre-scale quartz veins or as narrow sulphide-only veins. Sulphides occur as 1 mm size disseminations to 2–5 mm clots, centre-lines in quartz veins, and fine-grained (<1 mm) selective replacements of hornblende and biotite in vein halos. Disseminated sulphides are more common in the Lornex deposit than in the Valley deposit.

Most of the copper mineralization is spatially and temporally associated with the potassic-muscovite facies, and bornite occurs in two to three discontinuous, northwest-trending domains which flank the central dyke complex. The highest concentrations of molybdenite are mostly coincident with the copper mineralization in the Lornex deposit. Quartz–molybdenite–chalcopyrite ± bornite veins with weak sericite halos are inferred to post-date the planar quartz-bornite veins with coarse muscovite halos, although definitive cross-cutting relationships supporting this interpretation are lacking.

Molybdenite typically occurs as blebs or disseminations at the margin of the quartz veins or as rhythmic microcrystalline layers. Minor sphalerite, galena, tetrahedrite, and pyrrhotite occur as accessory sulphides.

The Highmont is approximately 1.6 km southeast of the Valley–Lornex deposit.