The Stuart (Ace) occurrence is located in the northern headwaters of the Goodspeed River, approximately 9 kilometres west-northwest of the western end of Nahwitti Lake.

Regionally, the area is underlain by northwest-trending belts of basaltic volcanics and carbonate sedimentary rocks of the Upper Triassic Karmutsen and Quatsino formations (Vancouver Group) and mafic volcanics and sediments of the Upper Triassic to Lower Jurassic Bonanza Group (Holberg volcanic unit, Nahwitti River wacke and Parsons Bay Formation). These volcanic and sedimentary rocks have been intruded by granodioritic rocks of the Early to Middle Jurassic Island Plutonic Suite.

Locally, bornite is disseminated in basalt and in quartz veinlets.

In 1928, a shallow pit was excavated (Minister of Mines Annual Report 1928, page 374).

During the late 1960s through 1974, BHP-Utah Mines and Cities Services Minerals Corp. completed programs of soil and rock sampling, geological mapping and ground geophysical on the area as the Expo and Pup claims. In 1973 and 1974, Cities Services Minerals Corp. completed induced polarization surveys on the area as the Pup claims.

In 1982, BHP-Utah Mines completed a program of rock and soil sampling and a ground induced polarization survey on the area. In 1988, Moraga Resources Ltd. and BHP-Utah Mines completed a program of geological mapping and rock sampling on the area. In 1989, a further program of rock and soil sampling, geological mapping and seven diamond drill holes, totalling 764.4 metres, were completed on the area.

In 1997, Jordex Resources Inc. completed a 156.1 line-kilometre airborne geophysical survey on the area on behalf of Moraga Resources Ltd.

In 2005, Luminar Resources Corp. completed a program of rock, silt and soil sampling; geological mapping; a 2687.0 line-kilometre airborne electromagnetic survey and 18 diamond drill holes, totalling 3154.0 metres, on the area.