The Imperial occurrence is located on the southwest flank of Mount Monro, southwest of Surprise Lake, about 8 kilometres northeast of the community of Atlin.
The Imperial showing lies within a body of upper Mississippian to Permian ultramafic rocks of the Cache Creek Complex. These rocks are composed largely of peridotites, diorites and gabbros under variable degrees of shearing and alteration. The peridotites are often highly serpentinized, especially in the vicinity of local faults. These rocks have intruded into a volcanic package of the upper Mississippian to Permian Nakina Formation (Cache Creek Complex). This package is composed largely of greenstone and volcanic greywacke. Porphyritic felsic dikes are often associated with the veins and can carry a significant amount of gold.
The alteration is silica-carbonate (listwanite?) type magnesite/ankerite, quartz, calcite, talc, fuchsite and minor tremolite within serpentinite and quartz, calcite, ankerite and fuchsite within greenstone (Assessment Report 9868).
The Imperial occurrence comprises several parallel quartz-filled fissures. The main vein or lode varies from 0.3 to 2.1 metres in width and has been traced for a distance of over 150 metres. The vein strikes at 135 degrees with a dip of 55 degrees to the southwest. The vein attitude is very consistent. Mineralization in the vein comprises visible gold with variable amounts of chalcopyrite, galena and pyrite. Copper staining with malachite is common.
The original Imperial property was first staked in 1899. Gold had been discovered in a 150-metre-long quartz vein. A bunkhouse and a small stamp mill were built from funding by a syndicate called Nimrod. Two crosscut tunnels, and upper and a lower, were driven to intersect the discovered quartz vein. The mine was developed from 1899 to 1902 and was operated from two levels with over 150 metres of underground development. The western extension of the vein is faulted and it pinches to an unmineable width to the east. On the upper level, the mining width can reach 2.5 metres, but the vein pinches with depth as well as decreasing in grade. In 1900, the Nimrod Syndicate miners milled 245 tonnes from the upper level, which yielded 13.7 grams per tonne gold while the lower tunnel produced 23 tonnes ore, which yielded 5.1 grams per tonne gold.
In 1981, Anglo Canadian Mining Corporation undertook a combined geological, geochemical and geophysical evaluation of the Imperial group of claims. In 1984, Lear Oil and Gas acquired the Imperial property and adjacent properties and contracted out a program of geological mapping, soil sampling, and VLF-EM and magnetometer surveys. In 1987, Homestake Mineral Development Company Ltd. carried out 19 kilometres of grid line surveys, detailed geological mapping and the collection of 245 rock and 26 soil samples; the company then optioned the property.
In 1988, Homestake Mineral Development Ltd. reported that in 1933 a geologist from British Columbia Mines Branch took 14 samples from a 0.5 metre section of the upper tunnel vein over a length of 10.9 metres. These samples reportedly averaged 24.8 grams per tonne gold and 31 grams per tonne silver, but were not duplicated by Homestake geologists. The property was allowed to lapse and re-staked by J.G. Payne in 2000. J.G. Payne worked the property briefly during summers of 2000, 2004, and 2006-09 and comprised geological mapping, and rock, soil and silt sampling. In 2009, an additional claim was acquired by Payne. In 2011, J.G. Payne collected two rock samples for petrographic study. Both Nimrod adit portals are covered by rock talus (ca. 2011) and have never been found by Payne, although the approximate location is known. Payne found the old Nimrod bunkhouse and mill, now both collapsed.
In 2018-19, Brixton Metals Corporation carried out exploration on their Atlin Gold Project which included: a 1992 line kilometre, helicopter-borne high-resolution aeromagnetic geophysical survey over a 40 square kilometre area that hosts the historic Pictou (104N 044) and Imperial (104N 008) showings, as well as the Yellowjacket gold mine (104N 043); the collection of 1227 soil samples, 110 rock samples and 1 stream silt sample; and a 1599.24 metre, shallow diamond drilling program that included 4 NQ-sized holes drilled at the Pictou showing and 18 NQ-sized holes drilled at the LD showing (104N 098, 100). In 2019, diamond drilling, as well as rock, soil and stream sampling focussed on historic areas known to host orogenic gold mineralization, as well as the Fourth of July batholith, Union and Sentinel mountains and Spruce Creek.
