Roundtop and Middle mountains are located about 22 kilometres southeast of Barkerville. Yanks Peak is 11.5 kilometres southwest of Middle Mountain, between Little Snowshoe and French Snowshoe creeks.

The Cariboo quartzite showing consists of quartzite which occurs in several horizons within the Cambrian to (?)Hadrynian Snowshoe Group. Quartzites exposed in the Yanks Peak and Roundtop Mountain areas may not be part of the same formation. Two main types of quartzite are present in the Roundtop Mountain area. One type is a white to pinkish weathering micaceous to slightly feldspathic quartzite while the other type is medium grey weathering and micaceous. Extensive quartz veining occurs in the quartzite in places.

Five chip samples collected by the Geological Survey Branch in 1982 assayed 95.12 to 97.57 per cent silica over 50 metres (Open File 1987-15, page 20). Quartzite in the Yanks Peak area is more homogeneous. It is variable in colour and is generally massive and fine grained with well-sorted and well-rounded grains. Three chip samples collected by the Geological Survey Branch in 1982 returned 95.56, 97.18 and 98.92 per cent silica (Open File 1987-15).