Clamshell Lake

Clamshell Lake sits at the top of the Minnesota PCA grading rubric with an A, a mark reached by the cleanest lakes in Minnesota. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

A TSI near 42 places Clamshell Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. A maximum depth of 44 ft puts Clamshell Lake in the middle of Minnesota's depth distribution. Clamshell Lake covers 211 acres alongside 6.5 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Clamshell Lake ranks 34 of 120 in Crow Wing County — solidly in the upper half of the local distribution.

Clamshell Lake is on the Minnesota infested-waters list for zebra mussels — boaters should follow clean-drain-dry protocols when moving gear to or from the lake. Walleye are documented at Clamshell Lake, one of 18 fish species on record for the lake. A documented public access point at Clamshell Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. 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.