The Leishman occurrence is located approximately 8 kilometres southeast of Mount Carruthers, centered on a cluster of mineralized showings (Property File - Canadian Superior Exploration Limited, Maps from Company Files, c. 1973).

The showing comprises numerous copper occurrences within a diameter of approximately 3 kilometres. The mineralization occurs within Lower to Middle Jurassic Hazelton Group rocks which form an east dipping succession. The sedimentary rocks are predominantly from the Nilkitkwa Formation which overlies the Carruthers Formation (basalt and andesite flows, breccia and pillow breccia) and the Telkwa Formation (basalts, andesites, dacite and rhyolite flows, breccias, tuffs and minor sediments). The succession is partially repeated by northwest trending thrust faults. This succession is bounded to the east by the Carruthers thrust fault.

The mineralization occurs disseminated in tuffs and agglomerates. The dominant sulphide is chalcopyrite with lesser bornite and chalcocite. Copper mineralization also occurs in quartz veins and within shear zones. Commonly associated with the mineralization is pyrite, malachite staining and minor hematite.

In 2019, the British Columbia Geological Survey mapped northern Hogem batholith and surrounding areas, including east of Mount Carruthers. An assay sample was collected of a conglomerate or agglomerate from the Dewar Formation within the Upper Triassic Takla Group in Stikine terrane, approximately 800 metres northwest of the location for the Leishman showings. The assay sample of a maroon, matrix-supported, poorly-sorted pebble conglomerate with quartz veining and malachite alteration yielded a result of 1 per cent copper (Paper 2020-01, pp. 25-47).

Soil samples taken in 2008 by Amarc over their 'Huge North' claim covered much of the 1973 ARP 1-10 claim area, and although the Leishman MINFILE occurrence plot was covered by Amarc's Huge claims, it just missed coverage by Amarc's soil grid. The southwest corner of Amarc's soil grid came within a few hundred metres of the Leishman MINFILE showing plot. The 2008 Amarc soil grid revealed a 400 by 800 metre copper in soil anomaly at its southwest corner, just northeast of the Leishman plot (Figure 10.2.9, Assessment Report 30732). The anomaly is open to the west and south. The Leishman plot is also about 1 kilometre south of the long-lapsed ARP 1-10 claims which were soil sampled in 1973 by SEREM Ltd. See Figure 6.1 (Assessment Report 30732) which shows the ARP claims with significant copper anomalous areas on a good topographic base map.