Deepest Lakes in Minnesota: Top 25 Ranked by Depth (2026)
Lake Superior, which forms Minnesota's northeast border, is the deepest lake touching the state at 1,332 ft. Among lakes entirely within Minnesota, the deepest is in our top-25 list below. Below: the 25 deepest monitored lakes entirely within Minnesota, ranked by maximum depth.
Top 25 Deepest Inland Lakes in Minnesota
Ranked by maximum recorded depth (feet). Water quality grade shown for each.
Why Deep Lakes Matter
Depth is one of the strongest predictors of lake water quality. Deep lakes thermally stratify in summer, isolating cold, oxygen-rich bottom water (the hypolimnion) from warm surface water. This protects coldwater fish like trout and cisco, and limits the internal phosphorus cycling that drives algae blooms.
Most of Minnesota's deepest lakes are in the Arrowhead region — carved out by glaciers during the Wisconsin glaciation 12,000 years ago. The Boundary Waters Canoe Area Wilderness contains many of them.