The Klappan River occurrence is located on a ridge on the east side of the Klappan River, about 9 kilometres south of Tacostadia Mountain approximately 122 kilometres north-northeast of the community of Stewart.

The Klappan River coal showings were located, trenched and sampled by Dawson and Ryan in 1991 (Geological Survey of Canada Open File 2555). Trench BB90004 sampled a coal-bearing thickness of 7.10 metres containing 3.80 metres total coal. Vitrinite reflectance of the coal is 4.42 per cent VMax, or anthracite rank.

Evenchick and Thorkelson (Geological Survey of Canada Bulletin 577) assigned the rocks in this area to the Late Jurassic Skelhorne assemblage. This deltaic assemblage underlies the Groundhog-Gunanoot assemblage, the main coal-bearing unit of the Groundhog coalfield. The Skelhorne is a deltaic assemblage, comprising varicoloured siltstone, sandstone and conglomerate, with or without coal, with crossbedding, ripples, burrows, parallel bedding, bivalve coquina, and brown-, green-, and grey-weathering conglomerate. Strata at these showings are folded in a series of anticlines and synclines; the strike of axial planes strike at 095 to 104 degrees and have near-vertical dips (Cross section CCCC-DDDD, Geological Survey of Canada Bulletin 577).

See Arctos (104H 021), located 38 kilometres northeast, for discussion of the history of formation nomenclature of the Bowser Lake Group.