Gold mineralization occurs in veins associated with multiple faulting and folding events in the Coeur d’Alene Mining District. The mineralization occurs as gold- quartz veins associated with an orogenic deposit type. The orogenic system at the Golden Chest appears to have an association with igneous rock activity. Hence, the vein deposits may be described as intrusion-related orogenic gold. The principal vein being exploited at the Golden Chest Mine is associated with the Idaho Fault, which juxtaposes the quartzites of the upper Prichard Formation against finer-grained argillites, also of the upper Prichard Formation.

Veins occur adjacent to the Idaho Fault both in its footwall, and in its hanging wall. The mineralization occurs in two types of quartz veins, banded and massive. These veins are generally conformable to bedding in the Proterozoic age Prichard Formation. The banded veins, which occur primarily in argillite, contain, pyrite, arsenopyrite, galena, sphalerite and visible gold. Thicker, massive veins occur in quartzite and contain pyrite, galena, chalcopyrite, sphalerite, scheelite and visible gold.

Golden Chest includes both open-pit and underground operations.

The Golden Chest underground mine is accessed by primary decline ramp (MAR) with a complimentary escape-way incline ramp. The primary mining method is underhand drift-and-fill utilizing cemented rock-fill (CRF). During 2021, IDR mined a total of 17,180 tonnes of ore at an average grade of 5.32 gpt gold. The ore came from the 891, 842, 833 and 824 stopes. The decline (MAR) was extended at depth during 2021 to the 815 sublevel which required about 190 meters of ramp development and two exhaust ventilation raises were completed by IDR miners. A two-boom jumbo was added late in the year to accelerate MAR development.

In 2021, IDR continued its open pit mining operation which commenced in August of 2016. Mining in the Klondike pit advanced from the 1032 bench to the 1002 bench during the year. A total of 27,125 tonnes of ore at average grade of 2.92 gpt gold and 174,000 tonnes of waste were mined during the year. Ore tonnes and grade in the Klondike Pit were lower than modeled because of unmapped, historic stopes in the Klondike where high-grade material had been mined out by the old-timers.

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