The Iron Cap occurrence is hosted within limestone and dolomite of the Lower to Middle Ordovician, Active Formation. The occurrence is close to the eastern margin of the granitic, Sheep Creek stock of the Middle to Late Jurassic Nelson Intrusions.

Grey and white crystalline limestone and dolomite contain dis- seminations and blebs of sphalerite, galena, pyrite, and pyrrhotite in lensoidal zones which are less than about 35 metres long and 1 metre wide. The sulphides appear to parallel vague banding in the carbonates, but the length of the mineralized zone appears to be nearly at right angles to the banding. The mineralized outcrops weather to form a limonitic gossan on surface. A sample across 1.83 metres of the highest grade material assayed 0.34 grams per tonne gold, 418.29 grams per tonne silver, 17.9 per cent lead and 13.9 per cent zinc (Bulletin 41, page 107).

Five tonnes were mined in 1914 and 5,785 grams of silver and 2,268 kilograms of lead were recovered.

Workings on the property include two old shafts, a few bulldozer strippings and diamond drill holes made in 1951 and 1952. During 2008 through 2016, Yellowstone Resources Ltd. examined the area as the Sheep Creek property. In late 2016, Margaux Resources Ltd. optioned the property and in 2017 examined the area.