Springpole Gold Project

Project Overview:

The Springpole Gold Project is located in northwestern Ontario on an area of approximately 800 hectares. The broader project land package covers an area of 41,943 hectares and consists of 30 patented mining claims, 282 mining claims and thirteen mining leases. The project is located approximately 110 kilometres northeast of the Municipality of Red Lake in northwestern Ontario and is situated within the Birch-Uchi Greenstone Belt. The large, open pit resource is supported by significant infrastructure, including an onsite camp, winter road access, a logging road within 18 km of the camp, and nearby power lines within 40 km.

With 191 Mt at 0.78 g/t Au and 4.6 g/t Ag, totalling 4.8 million ounces of gold and 28 million ounces of silver in the Indicated Mineral Resource category, and 64 Mt at 0.38 g/t Au and 3.1 g/t Ag, totalling 0.8 million ounces of gold and 6.5 million ounces of silver in the Inferred Mineral Resource category, the Springpole Gold Project is one of the largest undeveloped gold projects in Ontario.

Birch Uchi Greenstone Belt Project:

The Birch-Uchi Greenstone Belt Project (“BUGB Project”) represents regional scale exploration opportunities that have been consolidated by First Mining surrounding the Springpole Project. This land tenure coupled with the Springpole Project, also located in the Birch-Uchi Greenstone Belt, consists of >70,000 hectares and presents a strong opportunity for new discoveries in an area that is historically underexplored and has only seen a fraction of the exploration work that has been done in the neighbouring Red Lake and Pickle Lake greenstone belts that have been subject to earlier consolidation and discovery cycles.

The BUGB Project hosts significant geologic elements, including historic production centres that are demonstrative of a strong gold endowment and affinity for new discovery. First Mining’s extensive BUGB property position is located within the Red Lake Mining District and is situated approximately 80 km east of the Red Lake Mines Complex of Evolution Mining and 75 km northeast of Kinross Gold’s Dixie Project (formerly owned by Great Bear Resources Ltd). The geology of the region is comprised of Archean Greenstone terranes that are endowed by significant gold mineralization inclusive of orogenic and alkaline intrusion related deposit styles. Initial data compilation and validation to date has indicated that the region demonstrates an underexplored and previously fragmented exploration immaturity that is well levered to the Company’s strategy of consolidation and district screening. 

First Mining has initiated district-scale screening of the Birch-Uchi Project area through a multi-phase commitment to explore and enhance mineral potential within the region.

Project Highlights:

One of the largest, undeveloped, open-pit gold deposits in Canada

• Reserves of 3.1 million ounces gold at 0.94 g/t, 16 million ounces of silver at 4.9 g/t
• Average annual gold production of 330,000 ounces in years 1 through 5

Positive Economics

• PFS announced November 2025, post-tax NPV_5% of US$2.1 billion and post-tax IRR of 41%

Tier 1 Mining Jurisdiction

• Long history of gold production in the area

Unique Strategic Gold Asset

• One of the few projects in Canada able to produce more than 300,000 oz per year

Existing Infrastructure in Place

• 34-person exploration camp, winter road access, a logging road within 18 km of the camp, and nearby power lines within 40 km

2025 Pre-Feasibility Study (PFS) Highlights:

The PFS contemplates an open pit mine and milling operation, evaluating recovery of gold and silver from a 30,000 tonne-per-day operation.

Details of the 2025 Springpole PFS can be found in our news release dated November 18, 2025 as filed on SEDAR+ and on www.firstmininggold.com. The accompanying technical report will be prepared and filed in accordance with National Instrument 43-101 Standards of Disclosure for Mineral Projects ("NI 43-101") by the end of 2025.

Key 2025 PFS highlights include:

• US$3.2 billion pre-tax net present value at a 5% discount rate (“NPV_5%”) at US$3,100/oz gold (“Au”), increasing to US$5.6 billion at US$4,200/oz Au
• US$2.1 billion after-tax NPV_5% at US$3,100/oz Au, increasing to US$3.8 billion at US$4,200/oz Au
• 54% pre-tax internal rate of return (“IRR”); 41% after-tax IRR at US$3,100/oz Au increasing to 63% after-tax IRR at US$4,200/oz Au
• Life of mine (“LOM”) of 9.4 years
• After-tax payback of 1.8 years and reducing to 1.2 years at US$4,200/oz Au
• Initial capital costs estimated at US$1,104 million, sustaining capital costs estimated at US$323 million, plus US$40 million in closure costs (excluding plant closure)
• Average annual payable gold production of 330 koz per year (Years 1 to 5); 281 koz per year LOM
• Total net cash costs of US$742/oz (Years 1 to 5); and US$802/oz LOM
• Net All-In Sustaining Costs (“AISC”) of US$877/oz (Years 1 to 5), and AISC US$938/oz (LOM)

Mineral Resource Statement Inclusive of Mineral Reserves (effective September 30, 2025)

The Mineral Reserves for the Springpole Gold Project are based on the conversion of Indicated Mineral Resources within the current pit design. The Springpole Gold Project Mineral Reserves are shown below:

Springpole Proven and Probable Reserves