The No. One occurrence is located at an elevation of approximately 1140 metres on an east-northeast–facing sloping, south of Cedar Creek and approximately 2.7 kilometres west-northwest 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.

The No. One occurrence occurs in the ‘No. 1 Limestone,’ which is intercalated between dark-grey argillites of the Mississippian to Permian Milford Formation. Small intrusions of ‘gneissic granite’ are reported in the vicinity of the deposit.

The deposit consists of replaced limestones along a shear zone (northwest 45) and brecciated hostrocks near or at the upper contact of the No. 1 Limestone with black argillites. The ore is generally oxidized, consisting mainly of iron oxide, some lead carbonates and wide silver and forming a dark brown, decomposed mass. Original sulphides are observed in places. Gangue consists mainly of calcite with locally some siderite and quartz growing in cavities in the calcite cement. Limestones in the ore are reported to be silicified.

During 1889 through 1929, the No. One mine is reported to have produced 36 441 tonnes of ore yielding approximately 62 014 685 grams of silver, 7371 grams of gold and 135 522 kilograms of lead. Minor amounts of further production by leases in the 1930s through 1950s is reported to be likely.

Work History

During 1889 through 1929, the No. One mine was developed with approximately 345 metres of crosscutting, 405 metres of drifting and 114 metres of stoping on five levels connected by an internal shaft inclined at 60 degrees to the west. Open stopes and inclined workings are reported to extend to the surface above the first level.

In 1956, Highland-Bell Ltd. conducted a program of geological mapping on the area as the Big Bluff, Fred, Mar and Nick groups of claims. In 1967, Silver Eagle Mines conducted a ground magnetic survey on the War Eagle claim to the southeast.

In 1996, a program of prospecting and geochemical (rock, silt and soil) sampling was conducted by George Addie on the area as the Silver Hoard property. A sample (73362) of silicified limestone hosting galena-pyrite-sphalerite mineralization from a stope yielded 0.34 per cent lead, 2.48 per cent zinc and 126.7 grams per tonne silver, whereas a nearby sample (73365) of oxidized quartz assayed 3.33 per cent lead, 1.69 per cent zinc and 357.8 grams per tonne silver (Assessment Report 25055). Also at this time, five dump samples (73364, 73366 to 73369) yielded values from 0.06 to 0.28 per cent lead, 0.29 to 2.43 per cent zinc and 3.9 to 63.0 grams per tonne silver (Assessment Report 25055).

During 2007 through 2011, Goldcliff Resource Corp. completed programs of prospecting, geological mapping, geochemical (rock, silt and soil) sampling and an airborne geophysical survey on the regionally extensive Ainsworth Silver property. In 2011, samples from the mine dump assayed values of up to 880 grams per tonne silver, whereas other samples yielded from 180 to 220 grams per tonne silver (Sample 3201120026; Assessment Report 36055).

In 2015, Goldcliff Resource Corp. conducted a program of prospecting, geological mapping, geochemical (rock, silt and soil) sampling and a 4.1 line-kilometre ground electromagnetic survey on the area as part of the Ainsworth Silver property. A float sample (32015007) taken from the face of a historical trench yielded 31.6 grams per tonne silver (Assessment Report 36055).

In 2020 and 2021, Goldcliff Resource Corp. conducted a further program of geochemical (rock, silt and soil) sampling and a 508.0 line-kilometre airborne magnetic, electromagnetic and radiometric survey on the Ainsworth Silver property. Float samples from mineralized boulders and rocks, taken near some historical trenches located approximately 100 metres upslope from the No. 1 mine portal, yielded values of up to 335.0 grams per tonne silver, 8.25 per cent zinc and 0.63 per cent lead, whereas a dump sample (3202170078) assayed 1.61 per cent lead, 7.18 per cent zinc and 3553.0 grams per tonne silver (Assessment Report 40377). Also at this time, a rock sample (3202070025) of silicified limestone with fine-grained galena and sphalerite, located on the access road approximately 400 metres to the north, yielded 0.16 per cent zinc, 0.97 per cent lead and 16.95 grams per tonne silver (Assessment Report 40377).