Little Boy Lake

On the LakeGrade rubric, Little Boy Lake pulls an A: clarity at 11.0 ft and 14 µg/L of phosphorus put it in the top bracket for Minnesota. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

The lake sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. At 74 ft of maximum depth, Little Boy Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. At 1,452 acres, Little Boy Lake is one of the larger lakes in Cass County, with 10.0 miles of shoreline supporting multiple distinct use patterns. Little Boy Lake sits at rank 70 of 133 in Cass County, in the lower half of the local distribution.

Little Boy Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. Little Boy Lake's fishery is anchored by muskellunge, with 18 documented species in total — a destination water for muskie anglers. Public access is available — the lake is on the Minnesota PCA public-access list. Ice-out has been recorded 23 times at Little Boy Lake, with a median around Apr 23. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.