The Pyramid Hill occurrence is located approximately 93 kilometres northwest of Stewart, British Columbia, in an area referred to as the Bronson Corridor. Pyramid Hill is located approximately 3 kilometers south of Inel (MINFILE 104B 113), 9 kilometres southeast of the past producing Johnny Mountain mine (MINFILE 104B 107), and 14 kilometres southeast of the past producing Snip mine (MINFILE 104B 250).
The area is underlain by an undivided assemblage of sedimentary and volcanic rocks ranging from Upper Triassic to Jurassic in age, which are intruded by Middle Mesozoic phases of the Coast Plutonic Complex.
The stratified rocks are composed of submarine to sub-aerial fragmental volcanic rocks that are interlayered with sequences of argillite, banded siltstone, greywacke, conglomerate and minor impure limestone which are thought to be correlative with the Lower Jurassic Hazelton, Unuk River Formation or the Upper Triassic Stuhini Group.
Structurally, the rock units have a general northwest trend and have undergone regional greenschist facies metamorphism. They are strongly deformed and are cut by numerous northeast trending faults and fractures.
Pyramid Hill is underlain mainly by a southwest dipping, 450 to 500 metre thick succession of sedimentary and volcaniclastic rocks. The sedimentary rocks are predominantly thin-bedded, locally calcareous, pale to dark grey siltstones grading upwards into tuffaceous siltstones. Higher in the succession, the sequence is characterized by massive tuffs and lapilli tuffs. Numerous granodiorite and orthoclase porphyry dike-like apophyses of the Coast Plutonic Complex intrude both the siltstone and volcaniclastic units.
Varying degrees of sulphide-bearing skarn alteration is developed within the volcaniclastics and tuffaceous siltstones in areas adjacent to the intrusions. Skarn alteration is comprised of massive, medium- grained chlorite, plus or minus diopside, with lesser amounts of quartz and epidote, isolated clusters of coarse, brown garnet, scattered tremolite-actinolite and sulphides.
The basal siltstone unit is hornfelsed with secondary biotite, is siliceous and hosts pyrite-rich areas adjacent to the intrusives.
The skarn related mineralization at Pyramid Hill appears to be stratabound and has selectively followed a sequence of tuffs and lapilli tuffs within a bedded succession of siltstones and tuffaceous siltstones. A highly mineralized area occurs west of Pyramid Peak on the north side of a prominent saddle (refer to Pyramid Saddle 104B 323) and consists of stockwork veins, veinlets and disseminations of gold-bearing sulphides. On the east side of Pyramid Peak is a massive magnetite and minor chalcopyrite replacement zone in the vicinity of the skarn/siltstone contact. Apophysis of this magnetite body were traced for about 30 metres and continuous rock chip samples were collected at 1 metre intervals. In 1987, a 1 metre chip sample assayed 0.136 per cent copper, 1.75 per cent zinc, 2.9 grams per tonne silver and 0.17 gram per tonne gold. Another 1 metre chip sample assayed 0.028 per cent copper, 0.336 per cent zinc, 1.7 grams per tonne silver and 0.12 gram per tonne gold (Assessment Report 16931, figure 5).
Other mineralization, associated with the magnetite skarn zones, consists of disseminations and stockwork veinlets which host some sphalerite, molybdenite, malachite and rare pyrrhotite in addition to the pyrite and chalcopyrite.
Exploration by Colorado Resources Ltd. in 2014 and 2015 included rock and channel sampling around Pyramid Hill and Pyramid Saddle as part of the larger KSP project. The general Pyramid Hill area is elevated in molybdenum, with 78 rock samples collected in 2014 reporting an average of 93 parts per million molybdenum (Assessment Report 35184).