- Altitude: 156 m above sea level
- Surface Area: 31,153 sq. km
- Mean Depth: 71.7 m
- Maximum Depth: 446 m
- Volume: 2,236 cu. km
- Shoreline Length: 2719 (+ 824 islands) km
- Drainage Basin: 114,717 sq. km
Great Bear Lake is the largest lake completely within Canada, but has a smaller volume than Lakes Superior and Huron which are shared with the United States. This deep, monomictic lake is located on the Arctic Circle where the Kazan area of the Canadian Shield and the Interior Plains meet. Although the lake was carved by glacial action during the last Ice Age, the basin shape has since been altered by isostatic rebound. Two sizable inflows are the Camsell and Johnny Hoe Rivers, but numerous small streams are also major contributors. The lake has a single outflow to the north – the Great Bear River, which is a tributary of the MacKenzie River. Great Bear Lake is covered with ice from late November to July. The main activity on the lake is sport angling for lake trout. Aside from changes in the average size of lake trout, Great Bear Lake has remained largely unaffected by human activity. There is no evidence of enhanced siltation, toxic contamination, eutrophication or acidification. Great Bear Lake is likely the largest lake in the world to presently exist in a pristine condition.
Great Bear Lake is surrounded by the natural landscape of the Taiga Plain. The Taiga Plain is characterized by flat topography, boreal forest, a subarctic climate, and an abundance of wetlands. The southern and western parts of the drainage basin are forested with black and white spruce interspersed with muskeg. The northern shores of the lake are near the treeline and tundra is the dominant vegetational zone. There are uranium and silver mines within the drainage basin.