The Free Coinage occurrence is between 2000 and 2200 metres elevation on the north side of Triune Creek, which drains to the northeast into Lardeau Creek. The Free Coinage (L.1588) tenure is immediately to the south of the past-producing Silver Cup mine [082KNW027]. The claim lies between the Silver Cup and Triune [082KNW026] properties.

In 1896, the tenure was owned and developed by Thos. Dunn and Wm. Farrell of Vancouver, who drove over 300 metres of drifts, crosscuts, raises and other workings looking for the southeast projections of the Silver Cup veins. In 1897, they sunk a 3.66 metres shaft on a vein that was thought to be the Silver Cup #2 vein; however, by 1924, there was some suggestion that it might be an intervening vein between the main Silver Cup vein and the Blind vein, and that crosscuts should be driven to the northeast and southwest to test this hypothesis. In 1899, the owners collared a tunnel at 2134 metres elevation and drove 168 metres to the southeast on the vein and, in 1900, added an 18.3 metres long crosscut in hopes of intersecting the main Silver Cup vein. The tenure was worked intermittently by lessees and a small shipment was reportedly made in 1901. George Yuill owned the claim in the 1920s, but no more work seems to have been done. The area was included in a large land package owned by American Chromium Limited in 1979. The company prospected the Silver Basin, Triune, Free Coinage, Morning Star, Copper Glance and Helco claims.

The Trout Lake area is underlain by a thick succession of sedimentary and volcanic rocks of the Badshot Formation and Lardeau Group near the northern end of the Kootenay arc, an arcuate, north to northwest trending belt of Paleozoic and Mesozoic strata that is now classified as a distinct, pericratonic, terrane. The arc rocks are bordered by Precambrian quartzite in the east and they young to the west, where they are bounded by Jurassic-age intrusive complexes. They were deformed during the Antler orogeny in Devonian-Mississippian time and were refolded and faulted during the Columbian orogeny, in the Middle Jurassic. A large panel, the "Selkirk allochthon", was later offset to the northeast by dip-slip motion along the Columbia River Fault.

The Badshot Formation is composed of a thick Cambrian limestone that is a distinctive marker horizon in the Trout Lake area. It is underlain by Hamill Group quartzite and it is overlain by a younger assemblage of limestone, calcareous, graphitic and siliceous argillite and siltstone, sandstone, quartzite and conglomerate, and also mafic volcanic flows, tuffs and breccias, all of which belong to the Lardeau Group. The rocks are isoclinally folded and intensely deformed, but only weakly metamorphosed. They occur as intercalated beds of marble, quartzite and grey, green and black phyllite and schist. Fyles and Eastwood (EMPR BULL 45) subdivided the group into six formations (Index, Triune, Ajax, Sharon Creek, Jowett and Broadview) of which the lowermost (Index) and uppermost (Broadview) are the most widespread. The Triune (siliceous argillite), Ajax (quartzite) and Sharon Creek (siliceous argillite) are restricted to the Trout Lake area. The Jowett is a mafic volcanic unit.

The Free Coinage claim straddles a major fault that cuts Lardeau Group strata north and south of Lardeau Creek. The eastern, hanging wall side of the fault is underlain by a minor amount of green phyllite of the upper part of the Index Formation, and by black, siliceous argillite and phyllite of the overlying Triune Formation. The assemblage is highly folded and deformed, and intruded by irregular, rusty weathering, dykes and plugs of diorite. The footwall side of the fault is underlain by phyllite of the Triune Formation. The rocks are schistose. The foliation displays the regional northwest strike of the area and has a moderate to steep dip to the northeast. The area of immediate interest is a band of schist between quartzite in the west and a mafic dyke in the east.

The Free Coinage lies immediately to the southeast of the Silver Cup mine and its is crossed by the same structures. Development work started on a small, conformable, northwest striking and northeast dipping quartz vein that was slightly mineralized with pyrite and galena on surface. The vein is in a shear zone that cuts black phyllitic slate in the footwall of an altered mafic igneous intrusion. It is 0.2 metre wide and contains streaks of galena and "a body of pyrite that carries gold". Most of the mineralization was on the footwall side of the vein. The workings were extensive and exposed numerous shears and several narrow quartz veins in tight fissures. Some of the faults and fissure veins contain a small amount of sulphide, but none are appreciably mineralized and no major shoots were identified. Many of the sulphide showings found in the adit are located where two structures intersect. At one locality in the main drift, a sphalerite-rich sulphide lens was found where a northwest trending, northeast dipping fissure intersected the main fault which, at that locality, had a northerly strike and steep easterly dip.