The Frisby Ridge (Big Slide) occurrence is located on the west flank of Frisby Ridge, at an elevation of approximately 1800 metres.

The area is within the Monashee Metamorphic Complex, which is regionally metamorphosed to amphibolite grade, and on the south eastern side of the Frenchmap Cap gneiss dome. Underlying rocks include dominantly granite orthogneiss and minor paragneiss of the core of the dome.

Locally, at the base of a quartz-mica granofels with some calc-silicate minerals and immediately above the underlying limestone, a thin layer of massive pyrrhotite with minor pyrite, sphalerite and traces of galena, chalcopyrite and bornite occurs as a discontinuous layer. The layer is 15 to 18 centimetres thick and can be traced for 600 metres on surface. In 1968, grab samples of the mineralized layer assayed up to 0.26 per cent lead, 7.91 per cent zinc and 20.5 grams per tonne silver, while grab samples of the altered wall rock assayed up to 0.52 per cent zinc and 13.7 grams per tonne silver (Assessment Report 1788).

Approximately 120 metres east of the main showing, a small outcrop of fault breccia composed of angular fragments of schist is replaced by pyrite and pyrrhotite. In 1968, a sample assayed 51.3 grams per tonne silver (Assessment Report 1788).

In 1968, King Resources prospected and mapped the area as the John and Nora claims. In 2007 and 2008, Silver Fields Resources soil sampled the area. In 2013, Silver Phoenix Resources completed a 111.0 line-kilometre airborne geophysical survey on the area.