CEO.CA Chairman's Briefing

CRANBROOK, BC / ACCESS Newswire / September 29, 2026 / Eagle Plains Resources Ltd. (TSX-V:EPL)(OTCQB:EGPLF) ("EPL" or "Eagle Plains") is pleased to announce that partner Sun Summit Minerals Corp. (TSX-V:SMN)(OTCQB:SMREF) ("Sun Summit") has completed the 2026 field program at Eagle Plains' Theory copper-gold project (the "Theory Project"), north-central British Columbia. The property is owned 100% by Eagle Plains, with 122 hectares of the property subject to an underlying 0.5% Net Smelter Royalty held by a third party.

The Theory Project borders Thesis Gold's Lawyers-Ranch Project to the north and is located within 10 km to the northwest of Sun Summit's JD Project. Sun Summit has an exclusive option agreement with Eagle Plains to earn up to a 100% interest in the project, located in the highly prospective Toodoggone Mining District. (see March 17, 2025 news release)

Highlights from 2026 Field Program

• Prospecting results in the Saboteur Zone, a 3km zone of chalcopyrite, bornite and chalcocite mineralization discovered in 2025, include THTHR094, a 2026 grab sample of a massive blue calcite vein with bornite and native copper. The sample was collected approximately 250m SE of 2025 sample BLTHR029 which returned 1.44% copper, 0.043 g/t gold, 12.8g/t silver; (Fig 2)
• Prospecting in the newly discovered Baguette Peak target area, approximately 600m SW of the Saboteur Zone, identified extensive chalcocite and chalcopyrite mineralization associated with a hydrothermally altered suite of volcanic rocks. Of particular note is THTHR086, a sample of strongly epidote altered basaltic andesite with malachite, bornite, chalcocite and cuprite. (Fig 3)
• A newly discovered zone north of Saboteur, named Misty Mountain, hosts numerous copper occurrences over a distance of 2.2 kms. The majority of mineralization is sub-vertically oriented calcite veins with variable amounts of malachite, bornite, chalcocite and cuprite.
• Airborne MagnetoTellurics geophysical survey ("MobileMT Survey") revealed strong anomalous resistivity associated with the Bev and Saboteur zones and aligns closely with anomalous copper samples taken in 2024 and 2025. The resistive zone seems also to closely map the presumed Jurassic-Triassic unconformity (~200 Ma), termed by the B.C. Geological Survey as the ‘red-line', which is observed throughout the Golden Triangle and Toodoggone regions to have a high spatial correlation to many known mineral deposits.
• The IP survey targeted the Bev to Saboteur zones and also highlighted strong resistivity associated with the red-line unconformity and demonstrated a broad >500m chargeability anomaly (single line) under the Bev Zone which overlaps with magnetic and resistive signatures, providing a priority target toward an interpreted causative source for anomalous copper in soil and rock samples taken over the past 2 seasons.
• A total of 218 rock grab samples, and 533 soil samples were collected: Geochemical and assay results are pending and will be reported after receipt and interpretation.

Theory Project 2026 Exploration Program

The 2026 work program built on the success from the 2025 field season, the first significant fieldwork on the property in over 30 years. (see January 21, 2026 news release)

The three phase 2026 fieldwork included an Airborne MT geophysical survey, a 20-day field program including prospecting, geological mapping, and geochemical sampling, and Induced Polarization (IP) geophysics in select target areas. Fieldwork was managed by TerraLogic Exploration Inc. of Cranbrook, BC, with helicopter and logistical support from the Sun Summit's JD Camp as required.

A total of 476 line-kilometers of airborne magnetotelluric ("MobileMT") surveying was completed in June at a nominal line spacing of 250 meters. The data imaged subsurface resistivity and will help locate causative intrusions and possible conduits for mineralization. The Mobile MT survey was completed by Expert Geophysics Surveys Inc. of Newmarket, ON, under the guidance of geophysicist, Andrei Bagrianski, P.Geo. Final deliverables helped to guide the second and third phases of fieldwork.

Phase 2 fieldwork was completed from July 19 - August 7, 2026 and included mapping/prospecting and rock and soil geochemical sampling with crews based out of temporary, helicopter supported, camps. Work focused on the detailed evaluation of targets identified by 2025 fieldwork, assessment of areas of interest generated by the MobileMT survey, and ongoing target generation and assessment in underexplored areas of the property.

Contour and grid soil geochemistry was completed north of the BEV Minfile occurrence, south of the Saboteur Zone, and east of Bornite Mountain. Prospecting and geological mapping focused on extending mineralization along the Saboteur and Bornite Mountain trends and around the BEV, Fred, DR and DM Minfile occurrences, and evaluating new targets at Baguette Peak.

Phase 3 consisted of 16-line km of IP surveys over high-priority target areas, including the Bev and Saboteur Zones. The geophysical work was caried out by Peter E. Walcott and Associates Limited.

The results from the 2026 work program will be analysed and modelled to identify and prioritize targets for 2027 drill testing. The work program had a budget of approximately $700,000.

Figure 1: Theory Compilation Map

Figure 2: THTHR094 - calcite vein with epidote, bornite and native copper

Figure 3: THTHR086 - strongly epidote altered basaltic andesite with bornite, chalcocite and cuprite

Highlights from 2025 Field Program

2025 work included:

• Data Compilation with rectification and analysis of historical surface sampling and reconnaissance mapping.
• Remote Sensing Acquisition of district-and property-scale datasets, focusing on VNIR and SWIR bands to identify mineral groups diagnostic of epithermal and porphyry alteration.
• Field Program consisting of prospecting, detailed geological mapping, and systematic rock, soil, and silt geochemical sampling on targets identified through data analyses.

Saboteur Zone: New high grade copper discovery

• 3km length zone of copper mineralization associated with coincident magnetic high transition zone and strong radiometric potassic alteration anomaly
• 15 of the rock samples collected returned over 1% Cu
• Grab sample LSTHR040: 4.78% copper, 0.635 g/t gold, 49 g/t silver;

BEV Zone:

• Broad copper soil and silt geochemical anomaly associated with multiphase alteration
• Grab sample BLTHR029: 1.44% copper, 0.043 g/t gold, 12.8g/t silver;

Fred-DM-DMR Zone:

• 1.6 km x 3km zone of copper mineralization associated with barite veining
• Grab sample BLTHR051: 6.42% copper, 0.088 g/t gold, 99 g/t silver;
• Grab sample JBTHR008: 0.65% copper, 12.6 g/t gold, 3150 g/t silver;

Petrographic analyses of 2025 samples identified strong epidote-chlorite-carbonate alteration directly with hypogene copper mineralization (chalcopyrite - bornite - chalcocite). This type of mineralization and alteration assemblage is interpreted to represent the inner shell of a porphyry system, which may indicate a proximal source for some of the Theory mineralization.

See Theory Project Information and Map here

The 9676ha Theory Project is located in northern BC within the Toodoggone Mining District. The district is endowed with both epithermal gold and porphyry copper-gold deposits, most notably the past producing Kemess Mine owned by Centerra Gold. The Omineca Resource Road provides access to the region from Mackenzie, BC. Recent road upgrades completed in 2023 by Thesis Gold on their Lawyers-Ranch Project brought road access to within 8 kms of the Theory Project.

Geology in the Theory region is primarily comprised of lower Jurassic Hazelton Group volcanics which unconformably overlie late Triassic Takla Group volcanics. The entire package of rocks is intruded by late Triassic and early Jurassic stocks. The majority of the Theory property encompasses the highly prospective Jurassic-Triassic unconformity (~200 Ma), termed by the BC Geologic Survey as the ‘Red-Line', which is known to have a high spatial correlation to many of the known deposits throughout the Golden Triangle and Toodoggone.

Exploration by previous operators has been intermittent since the mid-1960's and regional government surveys are sparse, however encouraging mineralization and alteration commonly associated with both epithermal and porphyry systems has been documented. The most significant documented work was completed in 1988 in the north and west areas of the Theory project area. Work consisted primarily of alpine ridge and subalpine prospecting traverses as well as reconnaissance soil sample lines in areas where no outcrop was present. This work documented occurrences of low-sulphidation epithermal-related mineralization including quartz-barite veins with up to 8.2 g/t Au, 195 g/t Ag, and 6.2% Cu at the DM occurrence (BC Minfile 094E 231)*; and a quartz carbonate vein system with up to 6.8 g/t Au and 1,480 g/t Ag at the Fred-1 occurrence (BC Minfile 094E 402)*. The BEV occurrences (BC Minfile 094E 259)*, interpreted as a Cu-Au porphyry target, returned select historical rock results up to 0.47% Cu, 10.5 g/t Ag, and 0.13 g/t Au. Detailed soils revealed a 1.6 by 2 kilometre copper-in-soil anomaly with peak soil results to 920 ppm Cu. Very little work is documented in the south and eastern parts of the property.

Recent exploration success in the area has been highlighted by Thesis Gold's announcement at their Lawyers-Ranch Project of a combined Measured and Indicated Mineral Resource of 4.0 Moz and an Inferred Mineral Resource of 727 Koz at respective grades of 1.51 and 1.82 g/t AuEq. (Thesis Gold, May 1, 2024 News Release) and by Amarc Resources' new high-grade copper-gold-silver discovery at the AuRORA zone of the Joy Project (Amarc Resources, January 17, 2025 News Release).

In late 2023 Eagle Plains acquired the property through staking and third-party agreements. After undertaking initial compilation and interpretation of historical data on the project, Eagle Plains completed a property wide, high resolution airborne magnetic and radiometric survey in July 2024.

Rock grab samples are selective samples by nature and as such are not necessarily representative of the mineralization hosted across the property. Management cautions that historical results were collected and reported by past operators and have not been verified nor confirmed by a Qualified Person but form a basis for ongoing work on the subject properties. Management cautions that past results or discoveries on proximate land are not necessarily indicative of the results that may be achieved on the subject properties.

Theory Project Option Agreement Details

To exercise the Option, Sun Summit must make a series of cash payments and share issuances to Eagle Plains and fund exploration expenditures on the Project. These payments, share issuance and expenditures are separated into two phases, with the first Option entitling the Company to acquire a 75% interest in the Project by paying CA$255,000, issuing an aggregate of 750,000 common shares to EPL and funding CA$3,000,000 in exploration expenditures on the Project by over a four-year term, including diamond drilling in years three and four. Pursuant to the second phase of the Option, the Company may acquire an additional 25% interest in the Project (for a 100% total interest) by notifying Eagle Plains of its intent to increase its interest to 100% and making an additional one-time payment of CDN$ 1,000,000 cash, of which half may be paid in Sun Summit shares valued at the time of notification.

If the First Option or the Second Option is exercised, a 2% smelter returns royalty will be granted to the Eagle Plains over the entire property, 1% of which may be repurchased for CA$1,000,000. Following the exercise of the First Option by the Company, the Company and the Vendor will form a joint venture which will administer the continued exploration and operation of the Project.

Eagle Plains will serve as Operator under the terms of Option 1 and will reserve the right to use Terralogic Exploration Services as geoscience consultant. Following the exercise of Option 1 and in the event of failure to exercise Option 2, Sun Summit and EPL shall then form a 75/25 joint venture ("JV") to further explore and develop the Property.

Qualified Person

Technical information in this News Release has been reviewed and approved by C.C. Downie, P.Geo., a director and officer of Eagle Plains, hereby identified as the "Qualified Person" under N.I. 43-101.

About Eagle Plains Resources

Based in Cranbrook, B.C., Eagle Plains is a well-funded, prolific project generator that continues to conduct research, acquire and explore mineral projects throughout western Canada, with a focus on critical metals integral to an increasingly electrified, decarbonized economy.

The Company was formed in 1992 and is the fourth-oldest listed issuer on the TSX-V (and the only one of these four that has not seen a roll-back or restructuring of its shares). Eagle Plains has continued to deliver shareholder value over the years and through numerous spin outs has transferred over $115,000,000 in value directly to its shareholders, with Copper Canyon Resources and Taiga Gold Corp. being notable examples. Eagle Plains latest spinout, Eagle Royalties Ltd. (CSE:"ER") was listed on May 24, 2023, and on October 30, 2025, ER shareholders overwhelmingly approved a three-cornered amalgamation that resulted in a reverse takeover of Eagle Royalties by Summit Royalty Corp. The resulting issuer is named Summit Royalties Ltd. and trades under the symbol SUM on the TSX Venture Exchange with a market capitalization of over $100M.

On October 2, 2024, Eagle Plains announced the formation of a separate division within the Company that will give Eagle Plains' shareholders direct exposure to strategic opportunities in Canadian green energy transition. As a wholly owned subsidiary of Eagle Plains, Osprey Power Inc. ("OP") will focus on identifying and advancing innovative and diverse clean energy project portfolios in target markets throughout Canada, with an initial focus on Western Canada.

Eagle Plains' core business is acquiring grassroots critical- and precious-metal exploration properties. The Company is committed to steadily enhancing shareholder value by advancing our diverse portfolio of projects toward discovery through collaborative partnerships and development of a highly experienced technical team.

Expenditures from 2010-2025 on Eagle Plains-related projects exceed $41M, the majority of which was funded by third-party partners. This exploration work resulted in approximately 50,000m of diamond-drilling and extensive ground-based exploration work facilitating the advancement of numerous projects at various stages of development.

Throughout the exploration process, our mission is to help maintain prosperous communities by exploring for and discovering resource opportunities while building lasting relationships through honest and respectful business practices.

On behalf of the Board of Directors of Eagle Plains

"C.C. (Chuck) Downie, P.Geo"
President and CEO

For further information on EPL, please contact Andrew Wilson at 1 866 HUNT ORE (486 8673)

Email: abw@eagleplains.com or visit our website at https://www.eagleplains.com

Cautionary Note Regarding Forward-Looking Statements

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release. This news release may contain forward-looking statements including but not limited to comments regarding the timing and content of upcoming work programs, geological interpretations, receipt of property titles, potential mineral recovery processes, etc. Forward-looking statements address future events and conditions and therefore, involve inherent risks and uncertainties. Actual results may differ materially from those currently anticipated in such statements.

SOURCE: Eagle Plains Resources Ltd.