Granite Creek Underground PEA: $155M NPV, 84% IRR
i-80 Gold Corp.'s Granite Creek Underground in Humboldt County, Nevada, USA has a Preliminary Economic Assessment (PEA) outlining an after-tax NPV of $155M and an after-tax IRR of 84%. The mine plan runs 8 years at about 59.6 koz Au per year.
i-80 Gold Corp.'s Granite Creek Underground has reported Preliminary Economic Assessment (PEA) results for the gold project in Humboldt County, Nevada, USA. The study headlines an after-tax net present value of $155M at a 5% discount rate. It reflects i-80 Gold Corp.'s (IAU.TO) latest disclosed economics for the asset.
Economics. The after-tax NPV is $155M using a 5% discount rate. After-tax IRR is 84%. All-in sustaining costs are pegged at 1597 USD/oz. Economics are based on $2,175/oz gold (base case); also shown at $2,900/oz and $3,000/oz.
Production and mine plan. The project envisions an underground operation. Life of mine is 8 years. Average annual production is approximately 59.6 koz Au. Average head grade is 11.6 g/t Au. Metallurgical recovery averages 78%.
These figures are extracted from i-80 Gold Corp.'s technical disclosures and reflect the most recent PEA on file. Compare this project against other developers and producers in our project economics database, and always verify the numbers against the original technical report before making any investment decision.
Reserves & Resources
| Category | Tonnage | Grade | Contained |
|---|---|---|---|
| Measured & Indicated | — | 10.5 g/t Au | 261koz |
| Inferred | — | 13.0 g/t Au | 326koz |
Our Analysis
- IRR after-tax
- 84%
higher than 88% of 105 projects we track
- NPV after-tax
- $155M
higher than 23% of 141 projects we track
- Mine life
- 8yrs
- Discount rate
- 5%
- Study price assumption
- $2,175/oz gold (base case); also shown at $2,900/oz and $3,000/oz
- Spot gold today
- $4,658.20/oz
The 84% after-tax IRR places this asset in the top quartile of the 105 gold projects we track, ranking higher than 88% of its peers. That is a genuine outlier on the return side, and it clears the roughly 15% after-tax hurdle developers typically need to secure project finance by a wide margin. But the NPV tells a different story: at $155M after-tax, it ranks higher than only 23% of the 141 gold projects we track. That disconnect is the first thing an investor should interrogate, and the answer lies in the project's scale and mine life, not its efficiency.
The 8-year mine life and the scoping-level PEA are the two constraints that matter most. A PEA's capital estimate carries a plus or minus 50% band, and with an NPV sitting well below the company's US$1.69B market cap, the funding risk here is minimal. This is not a single-asset bet; it is one of 9 projects we track for this company, a diversified portfolio that can absorb the execution risk of a preliminary study. The jurisdiction, Humboldt County, Nevada, is among the most mining-friendly in the world, which supports the study's assumptions being met in practice. The study uses a $2,175/oz gold base case, while today's spot sits at $4,658.20/oz, so the returns are not dependent on a heroic price deck, they are simply amplified by it.
The 5% discount rate is worth noting only because it sits at the low end of reporting convention, which flatters the headline NPV, but since nearly every study clears its own rate, it is not an investment signal. The real question is whether the market is discounting the PEA's preliminary nature or simply waiting for a feasibility study to confirm the grade and cost assumptions. If the project delivers at the scoping level, the IRR is exceptional; if the plus or minus 50% band cuts the wrong way, the NPV erodes quickly. The deciding factor is whether this asset can survive the transition from PEA to a defined reserve without a material downgrade in its economics.
Our take, benchmarked against the project economics in the Mining Stocks database. Figures are estimates drawn from company technical reports — not investment advice; always verify against the source filing.