The Towser occurrence is on the east side of Cup Creek, which drains to the north into Lardeau Creek. The Towser (L.1565) claim is between 1675 and 1750 metres elevation. It is down slope from the Sunshine (L.1564) claim, which is part of the Silver Cup mine property [082KNW027]. The Towser vein is on the projection of the Silver Cup vein system and the tenure is crossed by the mine's tramway and straddles its access road.
The Towser claim was originally part of the Silver Cup Group and it was extensively explored on surface and underground by means of adits and raises in the late 1890s. At that time, the Towser and neighbouring Sunshine claims were bonded to the Lillooet, Fraser River and Cariboo Gold Fields Company Limited, and Sunshine Mining Limited was established to carry out the development work. In 1899, the ground was acquired by J.M. Skeoff on behalf of Chicago interests. Later, in about 1915, C.T. Porter and Associates of Spokane acquired the property and a small amount of ore was shipped in 1917. By then, most of the early workings, which amounted to approximately 152 metres of drifting and cross-cutting on one level, were in place. The partnership still owned the property in 1929. Silver Cup Mining and Milling Company Limited installed a 32 tonne per day flotation mill in 1937 and proceeded to mill low-grade, sphalerite-rich ore from the Silver Cup and Towser dumps.
In 1972, True Blue Explorations Limited owned the Towser, Yuill [082KNW120] and Silver Cup [082KNW029] properties and conducted a limited work program. At that time the adits were open and some bulldozer trenching was done. Pandora Management Limited set up a jig and processed low-grade ore from the main dump the following year, however concentration proved to be difficult. By 1976, the Towser and Yuill properties where part of its Silver Chalice Group, owned by C.T. Exploranda Limited. The company drove a crosscut from the Yuill to intersect the Towser vein 75 metres below the Towser adit level. At the same time, C.T. Exploranda also cleaned out the Towser adit and described it as having 54.8 metres of crosscut, and 53.3 metres of drift "on a vein that is 1.52 metres wide but mineralized over widths of from 0.61 to 1.52 metres wide". The company suggested that the original workings had "wrongly" followed the schistocity, rather than the vein, for 30.5 metres. In the late 1970s, it drifted on the vein, conducted an underground diamond drill programme, drove a raise to surface and stoped some ore. Most of its later effort was on the Yuill vein on the Y 1500 level. In 1980, the company continued with further underground development work on the Yuill crosscut and the Towser vein. The crosscut was driven towards the Silver Cup vein, which was projected to lie to the southwest. There is a map of the underground workings in GCNL #51, March 13, 1985. It shows three, parallel, northwest trending veins approximately 60 metres apart. They are, from northeast to southwest, the Yuill, Towser and Silver Cup. Goldfever Resources Limited took over exploration in 1985 and continued to work underground on five, high-grade, lead-zinc-gold oreshoots. However, it too focused most of its effort on the development and mining of the Yuill vein.
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 Towser claim is underlain by black siliceous argillite and phyllite of the Triune Formation which is in two panels on either side of a major northwesterly trending fault. All the rocks are highly folded, deformed and schistose. The foliation displays the regional northwest strike and has a moderate to steep dip to the northeast.
The vein is weakly discordant and cuts siliceous slate. In 1899, it was described as "a strong vein of high-grade grey copper (tetrahedrite) and galena ore very similar to that found at Silver Cup". Later, in 1929, it was described as having well defined walls that strike at 163 degrees and dips steeply (approximately 70 degrees) to the northeast. The width varies considerably, but averages between 1.22 and 1.52 metres. The mineralization consists of pyrite, sphalerite, galena and some tetrahedrite and chalcopyrite in a gangue of quartz, carbonate and rock fragments. The quartz is white and generally coarsely crystalline; however, it locally contains vugs with finer-grained quartz. The sulphides occur in bunches and streaks. On surface, the vein has been exposed for 53 metres and is, on average, 1.52 metres wide. However, it is only mineralized over 0.61 to 1.52 metres widths.