The Montezuma property is located in the basin of Montezuma Creek, a northern tributary of Keen Creek, at an elevation of about 1790 metres. It may be reached by trail from the Keen Creek road.
This group of claims was located in 1891 by Messrs. Becker, McLeod, Rossiter and Sandon. Most of the exploratory work on the Montezuma (Lot 2041) and Mexico (Lot 2042) claims was done by the Kaslo-Montezuma Mining & Milling Co. of Seattle in the years 1898-1899. The No. 1 adit, driven 6 metres below the surface outcrop, showed pronounced mineralization along the foot and hanging-wall sections of the zone across widths of from 1.5 to 3 metres. No. 2 adit, 24.3 metres below No. 1, crosscuts to the same lode. A third adit, nearly 92 metres below No. 2 level, reached the lode by a long crosscut and was connected by a raise with the upper workings. Most of the ore was stoped from the upper levels over a maximum length of about 46 metres. Below No. 2 level the ore became lean and formed a more or less chimney-shaped mass. This ore was stoped out without, apparently, discovering further deposits. A mill was built on Keen Creek but it was destroyed by fire shortly after operations at the mine ceased.
The property was taken over by H. Giegerich of Kaslo in 1906. Development work underground was confined to the blocking out of a body of concentrating ore. About 90 tonnes of high grade galena was taken out in the process. The body of concentrating ore was taken out and very little has been done with the property since. A shipment of zinc was made from the mine dump in 1918. During 1950 B.W. Price and J.H. Lassen held a lease on the property. In 1951 Kootenay Belle Gold Hines Ltd. of Vancouver acquired ownership of the property and mined 33 tonnes of ore from the old workings. Operations of this company were suspended in 1952 and the assets taken over by the Canada Trust Company of Vancouver.
Regionally, the area lies on the western margin of the Kootenay Arc, in allochthonous rocks of the Quesnel Terrane. In the vicinity of the occurrence, the Quesnel Terrane is dominated by the Upper Triassic Slocan Group, a thick sequence of deformed and metamorphosed shale, argillite, siltstone, quartzite and minor limestone. Rocks of the Slocan Group are tightly and disharmonically folded. Early minor folds are tight to isoclinal with moderate east plunging, southeast inclined axial planes and younger folds are open, southwest plunging with subhorizontal axial planes. The sedimentary sequence has been regionally metamorphosed to lower greenschist facies.
West of the occurrence the Slocan Group has been intruded by the Middle Jurassic Nelson intrusions which comprise at least six texturally and compositionally distinct phases ranging from diorite to lamprophyre. The most dominant phase is a medium to coarse grained potassium feldspar porphyritic granite. Several feldspar porphyritic granodiorite dikes, apparently related to the Nelson intrusions, also cut the sedimentary sequence near the occurrence (Paper 1989-5).
The rocks underlying the Montezuma property are andalusite schist, phyllite, quartzite, calcareous argillite and limestone of the Slocan Group that have been affected by contact metamorphism due to the emplacement of the Nelson intrusions. The sedimentary rocks are folded in a vertical dipping series of isoclinal folds striking northwest and plunging steeply to the south.
Mineralization consists of galena, sphalerite, pyrrhotite and pyrite as replacement in limestone strata. The mineralization is in a chimney-like structure, 15 metres wide and 25 to 30 metres in length, which plunges 70 degrees southeast. The mineralized chimney has been explored with a gloryhole and two short adits. A grab sample from the dump near the portal of the upper adit assayed 446 grams per tonne silver, 12.85 per cent lead and 0.4 per cent zinc. The dump is estimated to contain 475 tonnes of material (Property File - Prospectus, Hilroy Mines Ltd., 1967). A 2 to 3 metre wide feldspar porphyritic dike that cuts the limestone beds near the mineralized chimney contains small amounts of pyrite, chalcopyrite and sphalerite concentrated in quartz veins. A chip sample taken from the mineralized porphyritic dike assayed 46 grams per tonne silver, 0.15 per cent lead and 0.3 per cent zinc across 1.5 metres (Property File - Prospectus, Hilroy Mines Ltd., 1967).
Production from the limestone-hosted mineralization between 1898 and 1951 yielded 1,679,159 grams of silver, 555,491 kilograms of lead and 136,314 kilograms of zinc.