First Mining Gold Discovers High-Grade Gold at Birch-Uchi Project in Ontario

• First Mining has discovered exceptional high-grade gold mineralization at its Birch-Uchi Greenstone Belt Project near the company’s flagship Springpole deposit
• New grab sample results from the Challenger target returned up to 25.60 g/t gold
• Mineralization occurs along a newly interpreted 60 meter strike trend which remains open in both directions
• The new discovery is located just 375 meters from recent successful drilling at the Saddle zone
• Results validate First Mining’s exploration methodology and highlight district potential

About First Mining Gold Corp.

First Mining Gold Corp. is a Canadian gold developer focused on advancing its 100% owned Springpole Gold Project, one of the largest undeveloped gold projects in Canada. The company’s portfolio also includes the Duparquet Gold Project in Quebec and a collection of exploration assets in Ontario and Newfoundland. Supported by an experienced management team and board, First Mining is positioned to become a prominent mid-tier gold producer.

New Near-Surface High-Grade Gold Discovered at Birch-Uchi

First Mining has discovered new high-grade gold mineralization at surface on its district-scale Birch-Uchi Greenstone Belt property (“BUGB”) located proximate to the company’s advanced Springpole Gold Project in northwestern Ontario, Canada. Recent exploration efforts led to the identification and sampling of the new Challenger target area where exceptional assay results confirmed two separate mineralized showings approximately 60 meters apart. Grab samples from newly exposed bedrock returned outstanding grades including 25.60 g/t Au, 7.10 g/t Au and 4.42 g/t Au.

Mineralization at Challenger: Geology & Structure

The high-grade mineralization occurs as an interpreted east-west trending structure with currently defined strike length of 60 meters based on surface sampling. Gold grades appear to be associated with a shear zone containing multiphase quartz veining and silica/carbonate alteration. The structure cuts through a granodiorite intrusive body in contact with surrounding turbidite sedimentary sequences. The system remains open in both directions along strike and at depth. Further mapping and sampling will aim to extend the known mineralized trend.

Proximal to Recent Drilling Success at Saddle Target

Significantly, the new Challenger discovery is located just 375 meters from First Mining’s recently drill-tested Saddle target which intersected 0.92 g/t gold over an impressive 114 meter interval. This confirms the potential for the area to host broader and continuous mineralized zones. First Mining’s technical team believes that the parallel structures surrounding the intrusive centre demonstrate excellent opportunities for additional gold discoveries.

CEO Views Challenger as a Major Exploration Advancement

First Mining’s CEO, Dan Wilton, commented on the significance of the Challenger discovery: “This discovery of a new zone of outcropping gold mineralization is a significant advancement in our regional exploration efforts for the Birch-Uchi Greenstone Belt project.” He further noted “Challenger represents a strong opportunity to further grow the Saddle area exploration opportunity through additional field campaigns.”

Mr. Wilton’s statements highlight the ongoing exploration success being achieved as a result of the company’s regional exploration methodology and the team’s improved targeting techniques.

Recent Exploration Success in Area Validates Approach

In addition to the high-grade Challenger discovery, First Mining has achieved notable exploration success over the past 18 months in the broader BUGB area:

• Winter 2023 Drilling at Saddle – confirmed 0.92 g/t Au over 114 meters
• Historical regional rock samples – returned up to 7.54 g/t Au, 4.8 g/t Au & 1.79 g/t Au
• 2022 mapping & sampling defined structures surrounding key intrusive
• Airborne geophysics refined drill targeting approach

This systematic approach of consolidating historical data, applying advanced exploration techniques and integrated 3D modelling have led the company directly to recent drilling and sampling successes – now culminating in the new Challenger discovery.

As James Maxwell, VP Exploration, stated: “We continue to demonstrate a growing exploration story in the renowned Red Lake Mining District...”

First Mining Leveraging Dominant Position in Emerging Ontario Gold District

The Birch-Uchi Greenstone Belt Project encompasses over 70,000 hectares of highly prospective geological terrain in the archean age Birch-Uchi greenstone belt. Despite limited exploration due to previous fractional land ownership, the BUGB hosts past small-scale high-grade gold production.

However, First Mining has consolidated a dominant land position covering over 40 kilometers of prospective stratigraphy. As a result, the company now has significant exposure to an underexplored gold district emerging between the world-class Red Lake gold camp operated by Evolution Mining and the Dixie discovery owned by Kinross Gold.

Recent exploration results across this district have demonstrated the potential for major new discoveries along the Birch-Uchi belt. Significant recent examples of million ounce-scale gold projects advanced in the region include Great Bear Resources’ Dixie discovery (acquired by Kinross) and First Mining’s own Springpole project.

Springpole Itself Shows District Potential & Scalability

First Mining’s flagship Springpole deposit hosts an existing open-pit resource of 4.7 million ounces grading 0.99 g/t gold. Metallurgical studies have shown the project can produce over 300,000 gold ounces per year in the first two years once in production. But perhaps most importantly, Springpole itself demonstrates that the Birch-Uchi greenstone belt can generate gold deposits which support scalable, district-sized mining operations.

As a proven mineralized system covering five kilometers of strike length and open at depth – all while surrounded by 70 kilometers of underexplored stratigraphy – Springpole shows the huge upside potential which still exists within this re-emerging gold belt.

Next Exploration Steps in the District

Building on recent exploration success and the identification of new mineralized occurrences, First Mining plans to advance its regional exploration efforts around the broader BUGB area through:

• Additional mapping & sampling to grow known zones and identify controlling structures
• 50 line-kilometer IP geophysical survey over high priority targets
• 5,000 meter diamond drilling program to test Saddle strike extensions and the new Challenger discovery plus evaluate other regional targets

Leveraging its consolidated land position within a geology analogous setting to the world-class Red Lake district, First Mining has a clear pathway to continue driving exploration advancements and make new high-grade gold discoveries across the underexplored Birch-Uchi belt.

Conclusion

Through systematic exploration guided by integrated data analysis and 3D modelling, First Mining has delivered encouraging results from the birch-Uchi Greenstone Belt over the past 18 months. Most recently, exceptional high-grade grab sample assays have identified the new near-surface Challenger discovery proximate to known mineralization at the Saddle target. Together with the advanced Springpole project, First Mining’s dominant land holdings in this re-emerging Canadian gold district offer investors significant opportunities for further exploration success and resource growth in the years ahead.