The Gray Creek Iron South occurrence is located on the west side of a ridge separating Gray and Baker Creeks.

The area is underlain by Middle Proterozoic rocks of the Purcell Supergroup and by Upper Paleozoic rocks of the Windermere Supergroup. Windermere rocks include conglomerate of the Toby Formation and quartzite, limestone, arkose and pebble conlgomerate of the Horsethief Creek Group. Purcell rocks include laminated argillite, dolomite and quartzite of the Mount Nelson and Dutch Creek formations.

Locally. bands of specular hematite occur in schist. The bands are up to 1 metre and strike north, dipping steeply west. The schists are underlain by dolomite. The original rock is thought to be a conglomerate of the Upper Proterozoic Toby Formation (Windermere Supergroup).

The Grey Creek Iron South iron showings were first mentioned in 1902. Claims were staked on the showings between 1952 and 1955.

During 2002 through 2009, Eagle Plains Resources completed programs of rock, silt and soil sampling, and 135.0 line-kilometres of airborne geophysical surveys on the area as the Sphinx property.