While deep in parts, several shallow bays and natural sand beaches make it a popular swimming spot.

The lake is a naturally self-sustaining lake and includes a large variety of fish, such as walleye, northern pike, smallmouth bass, largemouth bass, crappie, bluegill, sunfish, pumpkinseed and perch.

The lake's major outlet is Bear Island River, which has an old dam that also limits fish movement at low water.

Aquatic plants grow to a depth of 7 feet (2.1 m) and are sparse along most of the shoreline of Bear Island Lake.

Farther north, along the Canada–US border, is Round Bear Island, which is in Kabetogama Lake and is part of Voyageurs National Park.