Namakan Lake

Namakan Lake comes in at a B on the grading rubric — a respectable showing for a Minnesota lake of its size and depth. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

The lake sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. At 150 ft of maximum depth, Namakan Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. At 24,066 acres, Namakan Lake is one of the larger lakes in St. Louis County, with 319.9 miles of shoreline supporting multiple distinct use patterns. Among the 215 graded lakes in St. Louis County, Namakan Lake sits at rank 70, above the county median.

An invasive species record — spiny waterflea — has been logged at Namakan Lake; Minnesota PCA maintains the official infested-waters list. Walleye are documented at Namakan Lake, one of 18 fish species on record for the lake. The lake lacks a documented public access point, so visitor use is limited. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.