Shell Lake

Shell Lake grades an F: every scored parameter (clarity) rates poorly, placing it among the most stressed lakes monitored in Minnesota.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. Shell Lake reaches 15 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. At 493 acres, Shell Lake fits the Minnesota median for monitored lakes, with 8.3 miles of shoreline. Within the 187 graded lakes of St. Louis County, Shell Lake sits at rank 179, near the bottom of the county list.

No invasive species are currently listed at Shell Lake — the lake remains off the Minnesota infested-waters roster. Walleye are documented at Shell Lake, one of 8 fish species on record for the lake. The lake lacks a documented public access point, so visitor use is limited. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.