The Cliff claim is located on the lower east slope of Red Mountain, about 1.6 kilometres of Rossland. The Consolidated St. Elmo adjoins to the west.

The Cliff claim (Lot 921) was staked in September 1890 by Gay Ruder and the Consolidated St. Elmo (Lot 924) in October of that same year by Will Springer. Both claims were Crown-granted, in 1896 to J.R. Cook and associates of Spokane. The Cliff Gold and Copper Mining Company, Limited, was incorporated in 1899. Some further work was reported in 1904. The Granby Consolidated Mining, Smelting and Power Company Limited, acquired the property in 1910 and sorne development work was carried out. Exploration and development work to that date had been done in 15-metre shaft and 18-metre adit on the Consolidated St. Elmo claim and about 305 metres of drifts and crosscuts in 3 adits on the Cliff claim.

The claims were subsequently acquired by a Rossland syndicate headed by L.A. Campbell. Lessees shipped small tonnages of ore during the period 1933-1936.

Scheelite was discovered in the old workings in 1942 and The Consolidated Mining and Smelting Company of Canada (Limited) examined the property under an option agreement; diamond drilling totalling 67 metres was done on the Cliff claim.

The claims were held in 1968 by Continental McKinney Mines Limited under a lease agreement with an expiry date of July 1972.

The old workings are within the Lower Jurassic Rossland Group (Elise Formation) augite porphyry, known as the Rossland sill. The sill lies beneath siltstone and hornfels and is exposed on the eastern slopes of Red Mountain. The augite porphyry is a uniform dark green rock with phenocrysts of augite up to 3 millimetres across. The upper contact is planar and dips about 20 degrees west, concordant with the bedding of the siltstone and hornfels of the Rossland Group. Several narrow dykes or sills of augite porphyry occur within the hornfels which is rich in hornblende and disseminated magnetite. The augite porphyry appears to be intrusive into the siltstones and to have a narrow thermal contact metamorphic zone of hornblende-magnetite hornfels.

The Rossland Group rocks are intruded to the south by the Early Jurassic Rossland monzonite stock and to the north by the Middle to Late Jurassic Trail Pluton which is comprised of a granodiorite stock.

Mineralization on the claim consists of veins host pyrrhotite, pyrite, and chalcopyrite. These were explored and mined by over 310 metres of drifts and crosscuts in conjunction with adits on the Consolidated St. Elmo claim (082FSW135).

The ore consists of a series of shoots in which sulphides infill well defined fractures or faults. The ore shoots end abruptly against crosscutting dyke structures and the veins are disjointed by faulting. A vein in tunnel No. 2, dipping 40 to 50 degrees north consists primarily of pyrrhotite over a width of 7 metres. The auriferous pyrrhotite is also associated with pyrite and minor arsenopyrite. In tunnel No. 3 a vein dipping 43 degrees north is comprised of massive pyrrhotite with some chalcopyrite and pyrite. On the surface the vein ranges between 0.3 to 0.6 metre in width. In 1942, scheelite was discovered in some of the old workings. The scheelite occurs in many parts of the vein and for a few centimetres into the wallrock. It is mainly disseminated but in places forms streaks and patches 5 to 8 centimetres wide. The average WO3 content across mineable widths is considered low.

Native bismuth is found in ore from the Cliff property. In 1967, a polished surface of ore from the property indicated 1.4 per cent of the area was occupied by bismuth which has veined and replaced arsenopyrite and also appeared to have extensively replaced pyrrhotite.

Between 1898 to 1911 and 1933 to 1936, 1915 tonnes of ore was mined and produced 14868 grams gold, 99530 grams silver, and 24,195 kilograms copper.