The Mammoth occurrence is situated 15 kilometres south-southwest of Nelson. The area has been explored since 1917.

The area is underlain by Lower Jurassic Hall Formation (Rossland Group) sediments and Elise Formation volcanic rocks. Hall Formation clastic sedimentary rocks overlie the Elise Formation. These have been intruded by the Middle to Late Jurassic Nelson Intrusions.

The Mammoth property is situated marginal to the eastern edge of the Bonnington pluton (Nelson Intrusion) on the western limb of a regional syncline. Elise Formation volcanics form a 200 to 500-metre-wide belt of north-striking, east-dipping flow sequences and fragmental rocks sandwiched between the Nelson Intrusions to the west and Hall Formation metasediments to the east. Monzonite to diorite porphyries occur as sill- or dike-like intrusions in the Elise-Hall contact area.

The main mineralized zones are hosted within a 200-metre-wide belt of Elise Formation volcanics situated between the Bonnington pluton to the west and diorite porphyry to the east. The steeply east-dipping contact between the porphyry and volcanics appears to be the major control on copper and molybdenum mineralization.

Erratic but widespread molybdenum-copper, with minor lead-zinc-silver mineralization and traces of gold, occurs within and around skarn and contact zones. The skarn zones, containing scattered mineralization, are hosted in volcanic and sedimentary rocks. Mineralization occurs primarily as disseminated pyrite, molybdenite and chalcopyrite in skarn zones within Elise Formation augite porphyry and agglomerate adjacent to the Bonnington pluton. Locally, minor veins carry sulphides but, farther to the north (Keno, MINFILE 082FSW349), significant mineralization similar to the Fern mine (MINFILE 082FSW183) occurs. Tungsten was reported by Little in 1959 but this has only been verified geochemically.

Silicification, potassic alteration and skarnification are most common in the volcanic rocks. Most of the sulphide-rich areas occur at or near contact zones of volcanics with intrusive rocks. Although the hornfelsed argillites of the Hall Formation host significant disseminated pyrite and some localized pyrrhotite, no economic mineralization has been reported in these rocks.

Exploration in the area began in the 1800s. The discovery of placer gold led to a modest gold rush and the discovery and development of numerous polymetallic and gold-quartz vein systems. In the early 1900s, prospectors working near the Mammoth showing explored sulphide mineralization exposed at the surface. Between 1917 and 1940, several adits, open cuts and one 12.2-metre shaft were completed.

The Mammoth area received limited, sporadic attention until 1960, when Welland Mining Limited began porphyry copper-gold exploration on the property. Exploration work included geochemical sampling, geophysical surveying, trenching and diamond drilling. Between 1967 and 1968, 15 shallow diamond drill holes were completed. Welland Mining later allowed the claims to lapse.

Shortly after, Harry Sanders and Eric and Jack Denny restaked the property and conducted additional soil sampling. In 1979, on the recommendation of Robertson Research Canada Limited, Celcan Limited optioned the property from the Dennys and staked additional claims. In 1981, Robertson Research conducted an exploration program consisting of silt sampling, soil sampling, trenching and ground magnetic surveying (26 line kilometres). Results of the program outlined several geochemical and geophysical anomalies on the property. A follow-up program included extensive geochemical and geological mapping and ground magnetic geophysical surveying.

From 1981 to 1984, Greenwich Resources Limited carried out significant amounts of work including soil, silt and rock geochemistry, magnetometer geophysical surveying and geological mapping. In 1989, Euro Petroleum Corporation conducted a small geological and soil geochemistry program over the northern Keno claims.

From 1991 to 1992, on behalf of Katie Mining Corporation and Mammoth Resources Limited, CME Consulting Limited conducted a comprehensive exploration program of grid establishment, soil geochemistry, and magnetic and induced polarization geophysical surveying. Limited geological mapping and sampling were also completed.

Rossmin Explorations Limited acquired the property in 1996 and completed a program of detailed geological mapping on the 1992 grid area and additional soil sampling.

In the fall of 1998, Bluebird Minerals Limited drilled four short NQ diamond drill holes totalling 350.52 metres. Three of the four holes encountered economic grades of copper, molybdenum and gold mineralization.

In 2010, the area including the Mammoth showing was owned by Anglo Swiss Resources Incorporated as part of the southernmost claim group of the Kenville property. In 2010, on behalf of Anglo Swiss Resources, St. Pierre Geoconsulting Incorporated conducted airborne magnetic and electromagnetic geophysical surveys over the entire Nelson Mining Camp area.

Samples taken from surface trenches assayed up to 0.066 per cent molybdenum, 1.66 per cent copper, 15.8 grams per tonne silver, 0.08 per cent lead, 0.143 per cent zinc and 0.126 per cent nickel (Assessment Report 10416). Old drillcore samples assayed higher molybdenum values but the mineralization is very erratic. Only traces of gold have been reported.

The following results are from the 1998 drill program: drillhole MAM98-1 reported 2 metres assaying 1.72 grams per tonne gold and 1.05 per cent copper; drillhole MAM98-2 reported 1.23 metres assaying 1.47 grams per tonne gold and 0.94 per cent copper; and drillhole MAM98-3 reported 1 metre assaying 2 grams per tonne gold and 1.86 per cent copper (Assessment Report 25874, page 9).