The property is located on the southeastern tip of Gribbell Island, approximately 2.4 kilometres inland from Pilot Point.

An east dipping (60 degrees), 6 to 9 metre wide bed of marble, intercalated with schist is cut by hornblende-biotite quartz diorite of the Coast Plutonic Complex. The main showing is a bedded sequence of red garnet and white quartz, marble-epidote skarn, and diopside skarn, irregularly mineralized with bornite, chalcocite, and minor covellite as disseminations, streaks, and splotches. The showing occurs in a northeast plunging anticline and averages 5 metres in width. A 5.2-metre sample assayed 1.02 per cent copper, 13.7 grams per tonne silver and trace gold (Sevensma, 1971).

The occurrence was staked in 1900 as the Empress Group by Canadian-American Mining Company of Bellingham, Washington (previously known as the New Whatcom Mining Company). During that year development included trail-making, and four short adits. In 1901 the company drove a 91-metre adit at 366 metres elevation to tap the main ledge. In 1903 a wharf and tramway were built. A 58-metre adit was driven in 1904. During 1905 and 1906, the 1901 adit was continued to a length of 220 metres, and 35 tonnes of ore were removed, from which 31 grams of gold, 1306 grams of silver, and 372 kilograms of copper were recovered. The company was issued 6 Crown Grants (Lots 580R4-585R4) in 1911.

Phelps Dodge did some further work in 1964. The property was restaked under the Ox name by Balfour Mining Limited in 1970. They conducted geochemical surveying, trenching, and drilling of three diamond drill holes between 1970 and 1973.

Smaller showings occur in an easterly direction over a 152 metre length and 84 metre vertical depth.