Crane Lake

On the scoring rubric Crane Lake grades a D: clarity at 6.6 ft and phosphorus readings still being added keep it in the lower bracket for St. Louis County. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

A TSI in the eutrophic range signals a lake doing what nutrient-loaded waters do — supporting an active algal community at the cost of clear water. Crane Lake is unusually deep for Minnesota at 80 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. At 2,921 acres, Crane Lake is one of the larger lakes in St. Louis County, with 34.0 miles of shoreline supporting multiple distinct use patterns. Crane Lake ranks 153 of 187 in St. Louis County — at the lower end of the locally monitored distribution.

Crane Lake has at least one documented invasive species (spiny waterflea), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. Muskie are on the species list at Crane Lake, alongside the lake's 12 other documented fish. Public access is available — the lake is on the Minnesota PCA public-access list. The lake has a partial ice record — 6 observed ice-outs, centered near Apr 27. 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.