Namakan Lake

Namakan Lake pulls a D on the LakeGrade rubric — phosphorus loading and limited clarity hold it below the Minnesota average. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. At 150 ft of maximum depth, Namakan Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. Namakan Lake covers 24,066 acres alongside 319.9 miles of shoreline, large enough that conditions can vary meaningfully between bays. Within the 187 graded lakes of St. Louis County, Namakan Lake sits at rank 154, near the bottom of the county list.

Namakan Lake has at least one documented invasive species (spiny waterflea), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. Walleye are documented at Namakan Lake, one of 18 fish species on record for the lake. No formal public access is documented at Namakan Lake — most use is by shoreline residents and their guests. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.