The Ash Mountain SE occurrence is located on the southeast side of Ash Mountain in the Cassiar Mountains, about 94 kilometres north of the community of Dease Lake.

Skarn has formed at one place along the contact between granitic rocks of the Late Cretaceous Parallel Creek batholith and sediments of the Upper Paleozoic Lower Dorsey Complex. The Parallel Creek batholith has been dated by potassium/argon dating of biotite to be 78 +/- 4 Ma.

Skarn fragments with large amounts of magnetite and traces of scheelite have been found in talus (Bulletin 19, page 43).