The Leader occurrence is located on the Sawmill Creek fault near Angus Creek, approximately 7 kilometres south of St. Mary's Lake and at an elevation of 1800 metres.
Regionally, the area is underlain by Mesoproterozoic rocks of the Purcell Supergroup, including the lower members up-sequence of the Aldridge, Creston and Kitchener formations. Included within the sedimentary package are primarily sills but also dikes of the gabbroic Moyie Intrusions. The quartzite-dominated turbidites of the Aldridge Formation give way to quartzites and siltstones of the Creston Formation. Granitic intrusives in the region are of two distinct ages and are very dissimilar. Mid-Proterozoic pegmatites of the Hellroaring Creek assemblage form sills, dikes, and small stocks that only intrude the Aldridge Formation. Much younger, likely Cretaceous, stocks such as the Angus Creek stock are composed of granodiorite to quartz monzonite.
Locally, a granodiorite stock has intruded rocks of the Creston and Kitchener formations. The intrusion is a leucocratic, porphyritic and non-porphyritic body with only modest alteration.
The Leader quartz vein appears to occupy a shear zone that juxtaposes Creston Formation rocks against Kitchener Formation rocks near the contact with a granodioritic intrusion. The vein varies from 0.15 to 1.5 metres wide and averages 0.45 metres wide. Mineralization consists of galena, pyrite, sphalerite, tetrahedrite, scheelite, chalcopyrite, hematite, stolzite and free gold. The vein strikes approximately north-south, dips east at 68 to 80 degrees and has been traced along strike for approximately 600 metres and to a depth of 50 metres.
Another zone of mineralization, associated with a magnetic anomaly, is reported approximately 1 kilometre to the northeast at an elevation of approximately 2100 metres. Locally, limonite altered granitic dikes host narrow, northeast trending, quartz veins with minor galena and chalcopyrite mineralization.
In 1915, samples are reported to have yielded up to 164.2 grams per tonne gold, 1966 grams per tonne silver, 69.5 per cent lead and 10 per cent copper (Assessment Report 13011).
In 1964, an 0.42-metre sample across the vein exposed near the adit portal yielded 13.7 grams per tonne gold, while sampling of vein material near the back of the adit or drift yielded 36.9 grams per tonne gold, 51.3 grams per tonne silver and 0.47 per cent copper over 0.15 metre (Assessment Report 661).
In 1983, a 0.57-metre chip sample from an open cut (No.7) yielded 20.5 grams per tonne gold, 361.2 grams per tonne silver, 12.10 per cent lead and 0.19 per cent copper, and a 0.33-metre chip sample from open cut No. 4 yielded 9.7 grams per tonne gold, 17.8 grams per tonne silver, 7.56 per cent lead and 1.38 per cent copper (Assessment Report 13011). Also, at this time, a 13.6 to 27.2 tonne bulk sample of random vein material yielded an average of 8.6 grams per tonne gold (Assessment Report 13011), and a channel sample over 120 metres yielded from 5.1 to 10.6 grams per tonne gold (Assessment Report 14112).
In 1985, diamond drilling yielded up to 11.6 grams per tonne gold over 0.60 metre (DDH 85.3; Assessment Report 14112).
In 2007, diamond drilling was performed on a north- trending shear, exposed in trenches approximately 400 metres to the northwest. A sericite-altered granodiorite with galena, sphalerite and chalcopyrite was intercepted from 33.2 to 34.47 metres depth and returned values of 3.04 grams per tonne gold, 394 grams per tonne silver, 2.40 per cent lead, 0.32 per cent copper and 0.06 per cent zinc over 1.27 metres (DDH G-07-02; Assessment Report 29665).
In 1964, a probable ore reserve of 662.2 tonnes yielding 14.0 grams per tonne gold, 85.8 grams per tonne silver and 2.85 per cent lead, with a possible ore reserve of 1560.4 tonnes yielding 14.0 grams per tonne gold, 89.6 grams per tonne silver and 4.09 per cent lead was reported (Assessment Report 661).
In 1915, the area was explored as the Mascot and Eclipse claims and development consisted of a 38-metre long adit or drift, a 16-metre deep shaft and several open cuts, all now caved. In 1932, the property was owned by J. Angus. In 1950, road construction to the property commenced but work ceased in October. In 1933, Estella Mines, Ltd., took option on the property and carried out general exploration. In 1955, the company changed its name to United Estella Mines. During 1962 through 1964, Royal Canadian Ventures completed programs of prospecting, geochemical sampling, trenching and geological mapping on the area as the Ursus claims. In 1973, Ursus Minerals soil sampled the area as the Jim claims. In 1980, the area was prospected as the Leader claim. In 1983, Donnex Resources completed a program of sampling, stripping and trenching and a ground electromagnetic survey on the area as the Leader A claim. Also, at this time, Hawk Resources completed a ground electromagnetic survey on the area immediately north as the Leader 2 claim, and Mustang Resources completed a program of soil sampling, geological mapping and ground magnetic and electromagnetic surveying on the area south and east as the Leader 3 and Lookout claims. During 1985 through 1987, Donnex Resources Ltd. completed programs of soil and rock sampling, geological mapping and five diamond drill holes, totalling 258.5 metres. During 1998 through 2002, programs of prospecting, rock sampling, geological mapping and a 9.3 line-kilometre ground electromagnetic survey were completed on the area as the Intrepid and Tick claims. In 2007, Ruby Red Resources completed a program of geochemical sampling and four diamond drill holes, totalling 462.4 metres, on the area as the Gar property. In 2009, a further program of soil sampling and three diamond drill holes, totalling 562.5 metres, was completed.