i-80 Gold Reports High-Grade Archimedes Underground Assays as Development Stays on Schedule

• Headline intercepts returned up to 24.6 grammes per tonne gold over 23.6 metres, leading five results from the Upper Archimedes zone that confirm mineralisation continuity across the upper 426 zone.
• 7,500 metres over 35 holes have been drilled to date at Upper Archimedes, largely completing the 2025 to 2026 infill programme, with the 36th and final hole expected in the second quarter of 2026.
• Approximately 1,200 metres of underground development was completed by the end of the first quarter of 2026, with construction advancing on schedule and project costs largely in line with budget expectations.
• First gold from Upper Archimedes is targeted in the third quarter of 2026, with Archimedes and Granite Creek underground material expected to begin feeding Lone Tree by late 2027, subject to refurbishment completion.
• An infill drilling campaign at Lower Archimedes targeting approximately 55,000 metres over 140 holes is anticipated to begin in the second quarter of 2026, ahead of an updated resource estimate and feasibility study expected in the first quarter of 2027.

i-80 Gold [TSX:IAU] [NYSE American:IAUX] is a Nevada-focused gold mining company building a mid-tier gold producer through a fully funded three-phase development plan. The company is the fifth largest gold mineral resource holder in Nevada and is pursuing a hub-and-spoke strategy centred on its Lone Tree processing facility following anticipated refurbishment.

Upper Archimedes Drilling Results

The Archimedes Underground Project sits at the southeastern end of the Battle Mountain-Eureka Trend in northeastern Nevada, on the Ruby Hill property. Upper Archimedes is the portion of the deposit above the 5,100-foot elevation level.

Headline intercepts returned grades of up to 24.6 grammes per tonne gold over 23.6 metres, with additional strong results of 10.2 grammes per tonne over 36.4 metres and 8.0 grammes per tonne over 46.4 metres. The programme also returned longer oxide intervals, including 6.1 grammes per tonne over 42.1 metres and 3.9 grammes per tonne over 44.3 metres.

True widths are estimated at approximately 40% to 65% of core width. The results confirm previously interpreted mineralisation in the upper 426 zone and demonstrate continuity, with potential to extend beyond the boundaries defined by the mineral resource estimate supporting the 2025 Preliminary Economic Assessment (PEA) and corresponding initial assessment.

Vice President, Geology of i-80 Gold, Tyler Hill, puts it this way:

"Drilling continues to return consistent and positive results that are improving our confidence in both the scale and continuity of mineralization at Archimedes. These results provide a solid foundation for ongoing development, and reinforce the broader potential of the Project."

Upper Archimedes Programme Status

Infill drilling at Upper Archimedes began in the fourth quarter of 2025. 7,500 metres over 35 holes have been drilled to date, largely completing the 2025 to 2026 programme. Results covering the first 20 holes of the programme have been released. The programme is expected to total 36 holes and be completed in the second quarter of 2026.

Results from the programme, together with further 2026 drilling, will support stope design for planned mining activities. The objective is to further delineate the zone ahead of the planned extraction of mineralised material.

Oxide Opportunity

Current drilling has intersected substantial oxide mineralisation not included in the 2025 PEA. The company is evaluating whether to integrate this oxide material into the mine plan and production profile, with that evaluation linked to the current gold price environment and an operating heap leach pad on site. Metallurgical testwork on the oxide material is underway.

Lower Archimedes Next-Stage Drilling

Lower Archimedes lies below the 5,100-foot elevation. Exploration drift development to serve as a drill platform commenced ahead of schedule in the first quarter of 2026.

Following completion of the Upper Archimedes programme, an infill drilling campaign targeting approximately 55,000 metres over 140 holes is anticipated to begin in the second quarter of 2026. Lower Archimedes remains open to the north, south, and at depth.

Development, Permitting & Production Timeline

Archimedes' construction began in the third quarter of 2025. The Upper Archimedes mining permit is in place, development footage exceeds plan, and approximately 1,200 metres of development were completed by the end of the first quarter of 2026. Project costs are largely in line with budget expectations.

Predictive groundwater models have been advanced, and an additional dewatering well was installed in the first quarter of 2026. First gold from Upper Archimedes is targeted in the third quarter of 2026.

Lower Archimedes permitting is underway, with an estimated completion by mid-2027, and opportunities to expedite are currently under review. Material from Archimedes and Granite Creek underground is expected to begin feeding Lone Tree by late 2027, subject to the proposed refurbishment being completed. Until then, Archimedes underground material will be processed through a third-party toll milling agreement.

Resource Base & Study Timeline

As of December 2025, Archimedes hosts an indicated gold mineral resource of 436,000 ounces at 7.6 grammes per tonne and an inferred gold mineral resource of 988,000 ounces at 7.3 grammes per tonne. The majority of the resource is hosted in Ruby Deeps.

The overall drill programme is primarily focused on infill drilling to enhance confidence in the mine plan, define the oxide-sulphide boundary, confirm continuity, and upgrade inferred resources into measured and indicated categories. The updated resource estimate is expected to incorporate approximately 60,000 metres of drilling, consisting mostly of infill. A new mineral resource estimate and feasibility study are expected in the first quarter of 2027. Mine life is estimated at approximately 10 years, with average annual gold output targeting approximately 100,000 ounces following ramp-up.