The Roosevelt occurrence lies approximately 15 kilometres northeast of Stewart and consists of the Silver and Copper adits. The Silver adit is on the west bank of Roosevelt Creek, a tributary of Bitter Creek, about 1.5 kilometres upstream from the confluence of Roosevelt and Bitter Creeks. The Copper adit is also on the west bank, about 200 metres further upstream than the Silver adit.
The area is underlain by north to north-northwest striking, predominantly west dipping slates and argillites of the Middle Jurassic Salmon River Formation (Hazelton Group) (Bulletin 63). These rocks are commonly deformed by north trending folds and faults. Dikes are conspicuous in the area. Granite, granodiorite and quartz monzonite dikes, typically up to 30 metres wide, trend northwest and dip west. Crosscutting, much narrower diabase or lamprophyre dikes are less common.
Two mineralized veins have been developed in the past: the Silver adit vein and, about 200 metres to the northeast, the Copper adit vein. The Silver adit vein has been developed by two adits: an upper (older) one and a lower one. The latter provided access to a mining level and haulage drift. The north-northwest trending vein is in sheared and crushed argillite and slate along the hangingwall of a parallel, fresh porphyritic granodiorite dike. The dike, dipping southwest at 54 to 67 degrees, is cut by small cross faults. The vein comprises quartz-calcite-sulphide stringers and lenses that range up to 0.5 metre wide. Sphalerite, galena, pyrite, chalcopyrite and tetrahedrite are erratically distributed. Breccia, formed by argillite clasts in a quartz-calcite-sulphide matrix, is common.
The Silver adit vein was mined over a length of about 35 metres from a stope about 3 to 5 metres wide and 15 to 20 metres high. A sample was collected in 1984 from a sulphide-rich lens in the back of the crown pillar, 15.1 metres from the portal. This sample assayed 0.8 gram per tonne gold, 446.7 grams per tonne silver, 10.8 per cent lead, 16.0 per cent zinc and 0.63 per cent copper across a width of 0.63 metre (Assessment Report 13352). A composite muck sample from the stope (representative of hand-sorted ore) assayed 0.5 gram per tonne gold, 429.2 grams per tonne silver, 9.6 per cent lead, 1.1 per cent zinc and 0.58 per cent copper (Assessment Report 13352).
The Copper adit vein has been developed by two old adits in the past: a lower adit, about 30 metres long, and a short, upper adit about 12 metres above the lower one. The west-northwest trending, steeply southwest dipping Copper adit vein comprises quartz containing disseminated pyrite and chalcopyrite. It is 12 to 48 centimetres wide, but averages 28 centimetres in width. The vein lies along the hangingwall of an intensely altered and silicified, parallel, light green dike that contains chalcopyrite and pyrite. A parallel fault zone, containing crushed and sheared argillite and quartz veinlets, forms the hangingwall to the quartz vein and separates the vein from well bedded, relatively undeformed argillite to the west. The vein-dike-fault system cuts across the strike of the bedding at a shallow angle. In places, the hangingwall fault and vein transect the dike itself. The vein extends the length of the adit. The sulphide content of the vein varies from 2 to 20 per cent. A channel sample collected in 1984 from the back of the lower adit and near the face assayed 38.9 grams per tonne gold, 14.4 grams per tonne silver and 0.17 per cent copper across 40 centimetres(?) (Assessment Report 13352). The Copper adit vein contains potential reserves of 18 tonnes per vertical metre over a length of 24 metres (Assessment Report 13352).
The Grizzly group of four claims, the first claims to be staked in the Stewart area, was staked over the occurrence by Connor and partners in May, 1899. The property was subsequently acquired by the Grizzly Mining Company who carried out extensive exploration and shipped about 10 tonnes of ore to Tacoma in about 1900. The claims were then allowed to lapse and were restaked as the Roosevelt group of four claims by Chambers, Stark and Rainey in 1901. During 1901-10, intermittent exploration, primarily on the Roosevelt No. 1 claim (Lot 896), comprised opencutting and three short adits. The Roosevelt Mining Company was formed in 1910; the company charter was surrendered in 1932. A shipment of about 13.5 tonnes, probably from the Silver adit, was sent to Trail in 1915. Assays from the shipment were 8.9 grams per tonne gold, 3462.9 grams per tonne silver, 34 per cent lead and 8 per cent zinc (Assessment Report 8095). The claims were purchased by Feezey and Oliver in 1933. Minor exploration, including some drifting, was done during 1934-35. The claims were subsequently acquired by Rufus-Argenta Mines, formed in 1955. In 1966, the company name was changed to Crest Ventures Limited. During 1966-67, Crest Silver Company Limited, a subsidiary of Crest Ventures, acquired the claims and carried out geological mapping and cleaned out the old adits. In 1968, a 45 kilogram bulk sample from the Silver adit assayed 56.2 grams per tonne gold, 3737.2 grams per tonne silver, 1.03 per cent copper, 23.42 per cent lead and 12.28 per cent zinc (Assessment Report 8095). During 1970-73, Ardo Mines Ltd. optioned the property and carried out prospecting, magnetometer and electromagnetic surveys and surface drilling near the Silver adit (3 holes, totalling 40 metres), underground drilling in the Silver (7 holes, totalling about 285 metres) and Copper (5 holes), adits and underground development on both the Silver and Copper adits. The latter work included the emplacement of two drifts, for mining and haulage, about 7.5 metres below the Silver adit. An estimated 5000 tonnes was mined from a single shrinkage stope in the Silver adit during 1972-73. An unknown quantity was shipped to the Adams Milling Ltd. mill at the mouth of Bitter Creek in 1973. The operations ceased in mid-1973 due to severe dilution in the stope. During 1979-80, Beaver Gold Resources Inc. optioned the property and carried out mapping, rock and soil sampling, and drilled 3 holes (totalling 95 metres) from the haulage drift to test the mineralization below the lower drift. In 1984, the property was owned by Grey Silver Mines Ltd. That year Maralgo Mines Limited optioned the property and flew an airborne VLF-EM and magnetometer survey over the area and conducted geological mapping, prospecting and sampling near the occurrence. No further work was reported until 1989 when Grey Silver Mines performed geological mapping, sampling and soil surveys in the area. The following year Varitech Resources Ltd. conducted a program of geological mapping, prospecting, sampling and soil, VLF-EM and magnetometer surveys in the area. This work included resampling of the Silver and Copper adits.