The Chief-Earl occurrence is located at approximately 1100 metres elevation on an east-facing slope, west of Krao creek and approximately 2.1 kilometres southwest of Ainsworth.

Regionally, the area is underlain by hornblende schists, limestone and banded quartzite of the Upper Mississippian to Permian Milford Formation and basaltic volcanic rocks of the Carboniferous to Permian Kaslo Group. Granodioritic intrusive rocks of the Middle Jurassic Nelson Batholith are exposed to the west.

Locally, a historical trench and nearby adit expose a northwest-striking fault that dips 45 degrees southwest, hosting disseminated galena, sphalerite and pyrite mineralization between schists and limestones that have been intruded by an altered porphyry. Later, in 1980, diamond drilling in the vicinity of the historical trench intersected a 2- to 3-metre thick, graphite-bearing fault zone striking 140 degrees, dipping 45 degrees to the southwest and containing minor amounts of disseminated sphalerite and pyrite.

In 1980, drillhole 80-9 yielded 7.15 per cent zinc, 0.22 per cent lead and 31.2 grams per tonne silver over 0.8 metre (35.75 to 36.55 metres down hole), and a chip sample from the trench yielded 1.80 per cent lead, 3.50 per cent zinc and 97.1 grams per tonne silver over 1.2 metres (Assessment Report 08254).

Another zone of mineralization is reported to be exposed in a small historical trench located near the north end of the Black Chief claim, approximately 350 metres north of the previous adit and trench. The mineralization is composed of minor amounts of galena and sphalerite in a narrow, northwest-trending, nearly vertical quartz-carbonate vein in the hangingwall of surrounding limestone. Drilling on the zone, in 1980, intersected a 20-metre thick zone of fracturing, veining and alteration hosting fine- to medium-grained disseminations and veinlets of pyrite.

In 1980, drillhole 80-11, located near the Earl–Black Chief claim boundary, yielded 0.11 per cent lead and 72.0 grams per tonne silver over 1.0 metre (20.6 to 21.6 metres down hole; Assessment Report 8992).

Work History

Historical trenches, likely dating to the late 1800s or early 1900s, are reported on the Black Chief claim. In 1890, a tunnel was driven approximately 9 metres.

In 1979, David Minerals Ltd. conducted a program of geochemical (stream and silt) sampling on the area as the Peanut Butter claims of the Ainsworth property. The following year, nine diamond drill holes, totalling 926 metres, were completed on the Crow-Fledgling and Black Chief claims and 29 diamond drill holes, totalling 1772.4 metres, were completed on the Black Chief, Earl, Blackbird, Dictator, Glengarry, United and Last Chance claims.

In 2012, David Wallach prospected and rock sampled the area as the Ainsworth property.