The St. Elmo property is at 1710 metres elevation on the east side of Great Northern Mountain. It is at the head of Fissure Creek, which drains to the east into Ferguson Creek upstream from Ferguson. The St. Elmo (L.4581) tenure is one of several crown-granted mineral claims that straddle the border between NTS Map sheets 82K/11 and 82K/12. It is immediately to the east of the True Fissure (L.1097) claim. The tenure cluster covers the St. Elmo [082KNW062], True Fissure [082KNW030], Broadview [082KNW031], Great Northern [082KNW061] and Blue Bell [082KNW060] deposits.

The first showing in the area was found in 1890 on the Great Northern claim. Other discoveries soon followed, and the entire vein system was located before the turn of the century. Small-scale exploration and development was carried on by the locators, or bondholders, for a number of years. Mr. Hugh McPherson shipped 5.4 tonnes of hand picked ore from the St. Elmo in 1899, yielding 19.4 kilograms of silver and 1098 kilograms of lead. The True Fissure, St. Elmo and Blue Bell Crown-grants and four adjacent claims were bonded by G.F. Park and Associates of Cincinnati, Ohio, who incorporated the Ohio Mines Development Company Limited, in October 1906. They were then transferred to the True Fissure Mining and Milling Company, Limited which had been incorporated by Park and Associates, in September, 1907. True Fissure, and its lessees, conducted intermittent exploration and development programmes until around 1930, when the Latonia Milling Company was formed by Park interests to install and operate a mill. In 1937, True Fissure was reconstituted as New True Fissure Mining & Milling Company Limited and in 1945 Comara Mining & Milling Company Limited took over the operation. It extended the number of claims to 43 and completed 670 metres of surface diamond drilling on the True Fissure and St. Elmo claims. In 1949, the holdings were transferred to Columbia Metals Corporation Limited, who engaged Granby Consolidated Mining, Smelting and Power Company Limited to carry out exploration work in 1952. The St. Elmo workings comprise two unconnected adits and a winze from the upper adit. Exploration work during 1972 included electromagnetic and self potential surveys covering the St. Elmo, Blue Bell, True Fissure and Great Northern claims, and 1102 metres of diamond drilling, in 54 holes. The St. Elmo workings were badly caved by 1929. At that time, they consisted of a drift 53 metres long, a 12.2 metre raise to surface and a 6.1 metre deep winze.

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 True Fissure and related occurrences are in grits and phyllites of the middle division of the Broadview Formation in the core of a major anticline that is believed to be a large drag feature on the southwest limb of the main Silver Cup Anticline. The mine area is on the southwest side of the Cup Creek Fault, near the axis of the drag fold anticline, which strikes and plunges to the northwest. The area has been subdivided into four structural blocks by later faults. It is cut by the Great Northern Fault, which is a sinuous, northerly striking and relatively shallow easterly dipping reverse fault that separates the mine geology into eastern and western blocks. Both sided of the fault are disrupted by movement on the Broadview Fault, a younger, northeast trending structure. Most of the mineralization is in graphitic schists in the footwall of the Great Northern Fault. The geology of the mine area is described by Fyles and Eastwood (EMPR BULL 45). The Great Northern Fault is a gouge and breccia zone of variable width that has been more or less injected with quartz and carbonate and a lens-haped vein of quartz and carbonate follows the footwall of the fault for 365 metres from Fissure Creek to the True Fissure No. 1 adit, and may continue south to the Great Northern mine workings. The hanging wall of the vein is sharp but the footwall is locally highly diffuse. The vein is defined as having in excess of 50 percent quartz and carbonate. In some places it splits into several strands that are separated by quartz vein stringers in crushed country rock. The vein consists of massive, crushed, quartz and coarse-grained, buff coloured, ankerite and siderite. In the True Fissure mine, the "vein" may average approximately 10 metres in width but the siliceous upper portion may be only half that. Vugs lined with quartz crystals occur but are not common. The sulphide minerals are pyrite, sphalerite, galena, chalcopyrite, argentiferous tetrahedrite and possibly bournonite. They appear to have been introduced after the gangue.

The St. Elmo vein is in black silty phyllites in the footwall of the True Fissure and Blue Bell vein. The upper adit was stoped to surface and can be traced out by a series of depressions. The vein has a strike of 130 degrees and a dip of 40 degrees to the northeast. It is reported to have been from a few centimetres to 1.8 metres wide and composed of quartz, a little carbonate, pyrite, sphalerite, galena and tetrahedrite. The upper part of the raise is said to have been particularly rich in galena and tetrahedrite, whereas below that, sphalerite and pyrite were more abundant. According to Gunning (GSC MEM 161) a 182 tonne sample was shipped from the upper zone at some point, although it is not clear when. It yielded an average value of 3.08 grams per tonne gold, 2720 grams per tonne silver, 26.6 per cent lead and 9.07 per cent zinc. At the same time, a solid sample of "grey copper" (argeniferous tetrahedrite) assayed 17657 grams per tonne silver and 10.37 per cent lead. He shows that the galena post-dates emplacement of tetrahedrite. There was still a small amount of galena and sphalerite with quartz stacked near the portal in 1962, when Fyles and Eastwood (EMPR BULL 45) described the area. The lower adit evidently passed to the southeast of the main St. Elmo vein and encountered a different vein striking 070 and dipping 50 degrees to the north. This vein is in the hanging wall of a shear, it is 0.61 metre wide and consists of quartz and a little pyrite.

In 2006, Taranis Resources Inc. conducted an exploration program of the property containing the occurrence. The program included various sampling, a total field magnetic survey, and VLF-EM survey. Channel sampling was conducted at the St. Elmo occurrence and found mineralization over 1.80 metres (McDonough, B. (2013-06-03): Technical Report on the Thor Project, British Columbia, Canada).

In 2007, Taranis Resources Inc. conducted a total of 29.1 line-kilometres of grid fixed loop transient EM geophysical survey. Six anomalies were discovered across the property. Highlighted trench sampling taken at the St. Elmo occurrence graded 0.17 grams per tonne gold, 421.55 grams per tonne silver, 0.26 percent copper, 4.18 percent lead, and 4.32 percent zinc over 1.80 metres (McDonough, B. (2013-06-03): Technical Report on the Thor Project, British Columbia, Canada).

In 2008, Taranis Resources Inc. conducted a drilling program at the Blue Bell, St. Elmo, Great Northern, True Fissure, and Broadview zones.

In 2012, Taranis Resources Inc. conducted a total field, gradiometer and VLF-EM geophysical surveys across the property containing the occurrence. Soil sampling was conducted over the Great Northern Grid, and the Meadow Grid. Anomalies from the surveys were coincident with geophysical, and historical work. Geological mapping found five zones on the Thor property. Thor property. The SIF Zone, Gold Pit Occurrence, Scab Zone, Antiform Zone, and Great Northern Footwall Zone.