The Ash Mountain (AP) occurrence is located on Ash Mountain in the Cassiar Mountains, about 101 kilometres north of the community of Dease Lake.

Discontinuous skarn lenses occur in limestones within folded, faulted and metamorphosed argillites and quartzites of the Upper Paleozoic lower Dorsey Complex, intruded by quartz monzonitic rocks of the Late Cretaceous Parallel Creek batholith. Disseminated scheelite occurs in various skarns, with grab sample assays yielding up to 0.15 per cent WO3 (Assessment Report 8196). Anomalous tin values are probably due to tin substituting for iron in skarn silicates.

In 1978-79, Du Pont of Canada Exploration Limited conducted geological mapping and soil sampling (253) on the AP claims. The AP claims cover an old showing marked as "occurrence" on the 104-O Mineral Deposit - Land Use map. No old posts were seen during traverses but indications of hand blasting were noticed in the central portions of this group. The A claims were staked to cover anomalous tungsten (10 ppm in 80 mesh; Open File 561) in the creek draining the large cirque lake.The G claims were staked for protection and cover the gap formed between the A and AP groups.