The Ash Mountain occurrence is located on the northern side of Ash Mountain in the Cassiar Mountains, about 99 kilometres north of the community of Dease Lake.

Lenticular bodies of limestone dipping 80 degrees west occur within micaceous quartzite of the Upper Paleozoic Lower Dorsey Complex. The limestone has been skarnified in zones of contact with quartz monzonitic rocks of the Late Cretaceous Parallel Creek batholith. Scheelite occurs as disseminations or with quartz in crosscutting veinlets. Selected samples of vein material assayed up to 2.2 per cent WO3; up to 0.5 per cent tin occurs in clinopyroxene and garnet, probably substituting for iron. Vesuvianite contains up to 0.012 per cent beryllium (Bulletin 19, pages 42, 43).

In 1978-79, Du Pont of Canada Exploration Limited conducted geological mapping and soil sampling (253) on the AP claims (104O 023) located 2.8 kilometres north of the Ash Mountain occurrence. 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.