The Penny showing consists of very pure limestone and is situated on a west-flowing tributary, 2 kilometres east of the Toad River, 5 kilometres northeast of the confluence of Yedhe Creek and Toad River in the Muskwa Ranges, 6 kilometres south of the Alaska Highway (Keays, Robert (1989): Personal Communication).

The limestone is in the Lower Silurian Nonda Formation which consists predominantly of dark grey, thick-bedded dolostone and subordinate quartz sandstone; limestone is rare, generally restricted to the lower part (Geological Survey of Canada Memoir 373). In this area, the Nonda Formation is near the hinge zone of the north-northwest trending and plunging Muskwa Anticlinorium, a regional structure characterized by moderate folding and thrust faulting (Geological Survey of Canada Map 1343A; Geological Society of America, Geology of North America, Volume G-2, page 639). Here, the formation strikes north-northwest and dips moderately eastward into the slopes east of the Toad River over a strike length of 8 kilometres.

This particular limestone deposit comprises a 60-metres wide, 30-metres high outcrop of extremely pure, porcelaneous (cryptocrystalline), milky white, massive limestone (Industrial Minerals File - Keays, Robert (1989): Letter). A sample of the limestone assayed 56.05 per cent CaO, 0.35 per cent MgO, 0.11 per cent SiO2, 0.01 per cent Al2O3, 0.01 per cent Fe2O3, 0.01 per cent MnO 0.02 per cent Na2O, 0.01 per cent K2O, 0.01 per cent TiO2, 0.01 per cent P2O5 and 43.74 per cent ignition loss (Industrial Minerals File - Assay Certificate, Cominco Limited, 1989; Open File 1992-18, page 129).