The Rock Island Lake anomaly is located 20 kilometres north-northwest of the town of Little Fort, on the southern portion of the Crazy Fox property.
The property is underlain by Middle to Late Triassic Nicola Group volcanic sandstone, siltstone, and conglomerate overlying mafic breccias and massive to pillowed pyroxene-phyric basalt. Cretaceous granite and quartz-feldspar porphyry intrusions approximately 1.0 kilometres in diameter intrude the Nicola Group rocks. Locally, the units are intruded by a swarm of small dikes and contain local hornfelsing. The granitic rocks have been offset and twisted by northeasterly directed compression.
A multi-element anomaly for zinc, copper, cadmium, molybdenum, nickel, cobalt and antimony was discovered during the B.C. Geological Survey till geochemistry program in parts of 092P08 and 09 (Open File 2000-17; Fieldwork 2000). This anomalous sample is within a linear, north-northwest trending belt of till and soil geochemical anomalies that local prospectors traced for more than 10 kilometres in 1998 and 1999 (Fieldwork 2000). The linear anomaly appears to be along or near the contact between volcanic and overlying sedimentary rocks of the Upper Triassic Nicola Group, although the contact is locally marked by faults of the Rock Island Lake system.
The first claims on the Crazy Fox property were staked in 1938 for the Anticlimax molybdenum prospect. From 1938 to 1960, various molybdenum and tungsten exploration programs were carried out, with a major focus on the Anticlimax showings in the north and central portions of the property. In 1961, Bralorne Pioneer Mines optioned the property and carried out a limited program of trenching, induced polarization surveying and drilling. Rio Tinto optioned the property in 1965 and performed a detailed geological mapping program as well as trenching, soil and stream geochemistry, and various geophysical surveys. Between 1966 and 1969, Falconbridge completed several exploration programs including soil and steam sediment geochemistry, geological mapping, electromagnetic and magnetometer geophysical surveys, and a diamond drill program. Fourteen holes were drilled, totalling 1605 metres (5265 feet). In 1980, Amax of Canada Limited conducted a soil and stream sediment sampling program over the Anticlimax molybdenum prospects. Exploration of the multi-element till anomaly did not begin until the 1990s.
Between 1998 and 1999, soil, rock and till geochemistry work on the Crazy Fox property was conducted by Addie and Bourdon (Assessment Reports 26290 and 26291). They were unable to locate the source of the anomaly in outcrop or float, but they did reproduce a very strong multi-element geochemical anomaly in glacial tills up to 500 metres wide and eight to ten kilometres long. A coincident airborne magnetic anomaly striking 160 degrees runs from 1.7 kilometres east of the north end of Tintlhohtan Lake, and continues to the southeast into Demers Creek (Assessment Reports 26290 and 26291).
In 2000, Inmet Mining Corporation optioned the property and performed magnetometer and very low frequency electromagnetic geophysical surveys. Two magnetic anomalies were located. In 2001 and 2002, Cassidy Gold Corporation began exploration for volcanogenic massive sulphide deposits. Work performed included an electromagnetic survey, geological mapping and soil geochemistry sampling programs, and drilling a single hole in an effort to further define the strong multi-element till anomaly.
In 2005, Newmac Resources Incorporated carried out a soil sampling and trenching program over the Anticlimax A, B and C showings to the north, the results of which agreed with and elaborated upon earlier geochemistry work by Rio Tinto and Falconbridge. A 33-hole drill program was carried out in 2006 along with soil sampling and trenching. In 2007 and 2008, 13,331 metres of core were drilled and using the core, a detailed fracture study of mineralized veins and fractures within the lower fault plate was carried out. Several significant zones of molybdenum and tungsten mineralization were encountered. Further work in 2009 included geological and geochemical sampling programs and three drillholes totalling 610.2 metres, none of which intersected significant mineralization.