Spoon Lake

Spoon Lake carries a solid B grade — strong on most parameters, with measurements that hold up well across the summer season.

The lake's low TSI puts it in oligotrophic territory — the cleanest of the four trophic classes, but also the most vulnerable to nutrient-driven shifts. Spoon Lake is unusually deep for Minnesota at 85 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. Spoon Lake covers 256 acres alongside 7.5 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Among the 142 graded lakes in Lake County, Spoon Lake sits at rank 43, above the county median.

No invasive species are currently listed at Spoon Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Spoon Lake, which usually reflects a lack of formal fisheries survey work rather than an empty 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.