i-80 Gold Corp.

Granite Creek Underground is currently ramping up production and is expected to achieve commercial production in late 2026. The mine currently produces approximately 540 tonnes of ore per day and is operated by a local mining contractor with more than three decades of underground mining experience in northern Nevada. The mining rate is expected to rise to approximately 900 tonnes per day at full production supporting higher gold production. The PFS outlines an updated mine life of approximately 8.5 years with annual steady state gold production of approximately 75,000 ounces. The PFS incorporates the Project’s current operating costs, outlined in Table 6 and the Appendix.

Underground access is through portals located in the north wall of the CX pit. The main decline provides personnel and equipment access to all areas of the mine and can accommodate 30-ton haul trucks. Mining will be conducted using underhand drift and fill methods with cemented waste rockfill optimized for the Project’s ground conditions. Production drifts are 15 feet x 15 feet with a 14% decline. Mining of the Ogee and Otto zones are between the 4,790-foot level and 4,150-foot level and the decline to the South Pacific Zone is developed to the 3,950-foot level. Fresh air comes in from a fresh air portal at the bottom of the CX pit and is connected to the various workings through raises. The haulage ramp serves as an exhaust drift.

Production drift widths will be maintained at 15 feet or less to minimize dilution and enhance recovery. Underhand drift and fill mining is well suited for the ground conditions at the Project and allows for a high degree of selectivity, productivity, and safety for mine personnel. This mining method also results in backfill with superior geotechnical quality compared to thein-situ rock.