Long Lake

Long Lake sits at the top of the Minnesota PCA grading rubric with an A, a mark reached by the cleanest lakes in Minnesota. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

Trophically, Long Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. The lake's 115 ft maximum depth is in the upper tier for Minnesota — deep enough for cold-water fish to find refuge in summer. At 1,007 acres, Long Lake is one of the larger lakes in Cass County, with 16.0 miles of shoreline supporting multiple distinct use patterns. Long Lake ranks 3 of 133 in Cass County, putting it in the upper tier of locally monitored lakes.

Long Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. Walleye are documented at Long Lake, one of 14 fish species on record for the lake. A documented public access point at Long Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. Ice-out has been logged at Long Lake more than two dozen times, putting the median around Apr 21 — a useful baseline for tracking climate trends. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.