The Let occurrence is located about 85 kilometres east-southeast of the community of Dease Lake.

The area is underlain by upper Mississippian to Permian Cache Creek Complex rocks including metavolcanics (greenstone), metasediments and tectonically emplaced ultramafic rocks. The Cache Creek ultramafic rocks consist of peridotite, dunite and pyroxenite which are generally serpentinized.

Scattered grains of chalcopyrite and pyrite occur over a small area in a gossanous ridge zone. The zone is hosted in a sericite schist/metarhyolite unit.

In 1977, two holes were drilled by Westfrob Mines (Falconbridge Nickel Mines Ltd.) within 1 kilometre to the northwest of the above zone. Traces of chalcopyrite were reported in one of the holes drilled. Geochemical, induced polarization, electromagnetic and magnetometer surveys were also conducted over a large area.