The Butterfly Lake showing area is underlain by Pennsylvanian intermediate metavolcanic and metasedimentary rocks of the Stikine Assemblage. The showing occurs near the eastern margin of a small stock of the Late Triassic to Early Jurassic Copper Mountain Plutonic Suite, consisting of syenite to monzonite on the north and ultramafic rock on the south. This Stikine sequence is intruded by Late Early Jurassic granodioritic intrusions of the Cone Mountain Plutonic Suite within a few kilometres of the showing and granite intrusions of the Paleocene to Eocene Sloko-Hyder Plutonic Suite within several kilometres.

The area around Butterfly Mountain about 1 kilometre southeast of Butterfly Lake, is characterized by moderate folding with north to northwest striking chlorite-sericite foliation and tight to isoclinal chevron folds. Large quartz veins are common along the nose of the folds but are usually pure white and barren of sulphide mineralization. Fault and shear zones cut the package and are often traceable over large distances. Sulphide mineralization and gossanous zones are often associated with these areas. Fine grain east to southeast trending andesite dikes with 1 to 3 per cent pyrite/pyrrhotite is common in the area.

In late 1989, Coast Mountain Geological conducted a preliminary prospecting and mapping on the Phacops property on behalf of owner J. Tarnowski. The property consisted of the RB 27, Bryd 1, Bryd 2 and Butt 3 claims. During the program, a total of 18 rock samples were taken. Sample PHF-13 graded 0.144 per cent copper and 1.1 grams per tonne silver (Assessment Report 19881). The samples were taken in an area of andesite about 1-kilometre northwest of Butterfly Mountain. A total of 13 stream sediment samples were also taken. Sampling and mapping were also completed southeast of the Butterfly Lake showing and east of the Upper Brydon showing, on the north and west flank of Butterfly Mountain (Assessment Report 19906).

In 1990, Boa Services Ltd., on behalf of owner J. Tarnowski, collected and analyzed 26 silt, 10 soil and 18 rock samples over parts of the RB 27, Bryd 1, Bryd 2 claims. Float samples with up to 0.056 per cent molybdenum were found about 5 kilometres north-northwest of Butterfly Lake and other float samples grading up to 0.5 gram per tonne gold were found (Assessment Report 21225).