The lake sits on the sands and gravels of the Empress Formation, an aquifer 30 m (98 ft) below its surface that was laid down by retreating glacial meltwaters.

Big Lake is part of the 260 km (160 mi) long Sturgeon River that begins at Hoople Lake and flows east to the North Saskatchewan River.

The western bay of the lake provides rare nesting habitat for Franklin's gulls.

The Lois Hole Centennial Provincial Park is established on the shore of the lake.

On June 5, 2001 the lake became an Important Bird Areas site.