Island Lake

On the LakeGrade rubric, Island Lake pulls an A: clarity at 17.5 ft and 8 µg/L of phosphorus put it in the top bracket for Minnesota. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

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. A maximum depth of 40 ft puts Island Lake in the middle of Minnesota's depth distribution. Island Lake covers 184 acres alongside 3.6 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Among the 133 graded lakes in Cass County, Island Lake ranks 9 — in the top quartile locally.

Island 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 Island Lake, one of 13 fish species on record for the lake. A documented public access point at Island Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The lake has a partial ice record — 22 observed ice-outs, centered near Apr 19. 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.