The Yah occurrence is located near the community of Yahk, just to the east of the Moyie River (Assessment Report 19952).

Regionally, the area is underlain by the peri-cratonic Middle Proterozoic Purcell Supergroup, a thick succession of siliciclastic and lesser carbonate rocks. The Purcell Supergroup is well known for hosting a number of significant deposits that include the Sullivan (082FNE052) sedimentary-exhalative lead-zinc deposit and the Troy copper-silver deposit in Montana.

More locally, the area of interest is underlain by the Aldridge Formation. The Aldridge Formation is the lowermost division of the Purcell Supergroup and is composed of turbiditic siliciclastic rocks and numerous gabbro sills. The focus of exploration in the Aldridge Formation is the contact between the Lower Aldridge and the Middle Aldridge which corresponds to the time of deposition of the Sullivan deposit. In this particular area of the Purcell basin, the contact between the Lower and Middle Aldridge is somewhat enigmatic in that there is no recognizable facies change.

Structurally, the Yah occurrence lies to the east of the Moyie fault and is encompassed within the broad north trending and plunging Moyie anticline. A fault that follows the Moyie River valley occurs within 500 metres to the west of this occurrence.

A mineralized vein contains visible amounts of galena in an oxidized sulphide zone. The best reported grab sample of mineralized material contained 1.83 per cent copper and 72.9 grams per tonne silver (Assessment Report 19952). A diamond-drill hole approximately 500 metres to the west of this occurrence intersected very minor sphalerite and galena with associated pyrite and pyrrhotite (Assessment Report 20829).