Swan Lake covers an area of 119 square miles (310 km2), with an average depth of 7.5 feet (2.3 m), giving a contained water volume of 571,200 acre-foot (705,000,000 m3).

The Swan Lake drainage basin covers 3,880 square miles (10,000 km2) and extends into the province of Saskatchewan.

Explorer Thomas Simpson remarked when travelling through the area in 1837: The industry of man may, in some future age, convert this wilderness into a habitable land, as the climate is good, and barley, potatoes, and other vegetable produce have been raised at several points along Swan River.

The area also supports significant forestry, hunting, sport-fishing, tourism, and outdoor recreational activities.

Wetlands occupy 10% of the basin, mostly bogs and shallow ponds located in the headwater areas of the Duck Mountains and Porcupine Hills, as well as the Swan Lake marsh complex.