The L. H. deposit is located on the east slope of Columbia Kootenay Mountain, immediately north-east of the city of Rossland, British Columbia.
There is a detailed description of the geological setting and history for this property on the British Columbia “Minfile” site, current to 2020, to which interested readers are referred. A portion of this description is quoted below:
“The Columbia-Kootenay vein system is part of the ‘Main vein’ system, which forms a continuous, well-defined fracture system on a regional scale. The Main vein system trends 070 degrees for a strike length in excess of 1.0 kilometres and consists of mineralized fracture fillings that dip steeply north. Refer to the Le Roi deposit (MINFILE 082FSW093) for further details on the Rossland mining camp and the Main vein system.
The mineralized zone trends northeast and dips between 45 to 75 degrees northwest, passing through both the Columbia and Kootenay Crown grants. The mineralized zone follows a contact between biotite-bearing monzonite, which forms the hangingwall, and augite porphyry (Rossland sill), which forms the footwall and appears to have been replaced by the ore. The ore consists of both massive and disseminated pyrrhotite in a hard, fine-grained gangue with minor chalcopyrite. Arsenopyrite occurs in places with the auriferous pyrrhotite. Much of the ore, that [sic] is made up of sulphides in calcite and altered rock gangue, appears to be laminated. The vein is fairly continuous and varies in width from a few centimetres up to 10 metres of nearly solid pyrrhotite. A nickel arsenic Sulphur [Sic – sulfide?], gersdorffite, is reported to occur in small octahedral crystals in the sulphide ore and is associated with the massive pyrrhotite and chalcopyrite from the Columbia-Kootenay vein. Also, native bismuth and bismuthinite are associated with minor chalcopyrite. The ore shoots end abruptly against cross structures.”

Giles Peatfield comments:

For a property with little production and very low grades, the Columbia-Kootenay property has seen a substantial amount of exploration work over more than a century. It is of interest that it represents the apparent northeastern end of the principal vein structures in the Rossland Camp. It is also of interest as the location of the relatively rare nickel-arsenic sulfide gersdorffite.
The question of production from the Columbia-Kootenay deposit is not easily resolved. The official data, taken from “Minfile”, state that a total of 144 tonnes (158 tons) yielded 68,520 grams (2,203 ounces) of gold. However, there are conflicting reports that suggest these figures are strongly understated. Brock (1906) gave estimated production figures, to December 31, 1905, for several of the mines in the Rossland Camp, including the Rossland-Kootenay (12,878 tons) and the Rossland-G[rea]t. Western (12,331 tons). The latter mine is probably the Nickel Plate mine, lying to the west nearer to the centre of the camp; the former is probably the Columbia-Kootenay. Drysdale (1915) presented a “Longitudinal projection of Columbia-Kootenay Mine, Rossland B.C.”, showing the extensive workings on six levels, including some areas of stoping. Unfortunately, he did not provide coherent production data. Gilbert & Malcolm (1942), who had access to the records of the Consolidated Mining and Smelting Company of Canada Limited (CM&S), the owners of the property, stated that “The mine produced about 15,000 tons; the best ore contains much arsenopyrite.” Hardy (1986) quoted the small tonnage officially reported in Minfile, but then went on to say “About 9750’ of development was completed prior to 1898 and an estimated 15000 tons were produced from 4000 m (12000 feet) of development work; a total of 12805 tons averaged 0.38 oz/t Au. In 1940 reserves were estimated at 10000 tons of 0.15 oz/t Au.” Unfortunately, Hardy did not say where she obtained these figures. We may conclude that the mine probably produced a modest tonnage of low-grade, direct shipping ore, but the precise figures are not readily available.
Comment on Minerals Reported:
The minerals listed, with the exception of gersdorffite, were all reported by Höy and Dunne, (2001), although in some cases it would appear that they were simply referring to previous publications.
Amphibole Supergroup: Höy and Dunne (2001) reported actinolite in skarn.
Arsenopyrite: This is reported by most workers on the deposit.
Bismuth: Reported by Thorpe (1967).
Bismuthinite: Reported by Thorpe (1967).
Chlorite Group: Höy and Dunne (2001) reported “chlorite”.
Clinopyroxene Subgroup: Höy and Dunne (2001) reported “clinopyroxene” and “diopside” in skarn, but gave no more specific details.

Feldspar Group: Höy and Dunne (2001) reported “plagioclase” and minor “K-feldspar”, without specific details.
Garnet Group: Höy and Dunne (2001) reported “diopside-garnet” skarn, without details.
Gersdorrfite: This is the mineral of most mineralogical interest in the deposit. Hoffmann (1898) described “. . . small octahedral crystals distributed through specimens of an intimate association of massive pyrrhotite and chalcopyrite, from the Columbia-Kootanie [sic] property, . . . .” He gave no analytical data for the mineral observed; however, later in the report he stated that Mr. [F. G.] Wait had analysed “An intimate association of pyrrhotite and chalcopyrite, through which was disseminated a little gersdorffite, in a somewhat calcareous gangue.” Of interest here is that Wait found only a trace of cobalt. Hoffmann (1892) had previously reported the first Canadian occurrence of the mineral, at the O’Connor claim, Denison Township, Ontario –analysis of this mineral by Mr. R. A. A. Johnston showed major amounts of arsenic, sulphur and nickel, with lesser amounts of iron, cobalt and copper. His description of the crystals was similar to that of those from the Columbia-Kootenay deposit. Drysdale (1915) reiterated Wait’s information. Johnston (1915) and Traill (1970, 1983) mentioned the previous reports but gave no additional data. Also of interest is the fact that Thorpe did not mention gersdorffite – this may simply be a case of his not collecting appropriate material to observe what is an uncommon mineral. Unfortunately, there is no information allowing one to state which of the three polytypes (Back, 2022) is represented here.
Magnetite: Thorpe (1967) and Höy and Dunne (2001) reported magnetite.
Mica Group: Höy and Dunne (2001) reported “biotite” in the vein gangue.

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11 valid minerals.

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