Ethel Lake

On the LakeGrade scale Ethel Lake grades a B, with clarity at 14.6 ft and phosphorus readings still being added placing it above the Minnesota median. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

A TSI value of 39 puts Ethel Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. At 64 ft of maximum depth, Ethel Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. At 191 acres, Ethel Lake fits the Minnesota median for monitored lakes, with 3.2 miles of shoreline. Ethel Lake sits at rank 55 of 97 in Otter Tail County, in the lower half of the local distribution.

Zebra mussels have been documented at Ethel Lake, which alters the filter-feeding balance and can paradoxically increase water clarity while disrupting the food web. The fishery includes walleye alongside the lake's other 13 documented species — a notable draw for Minnesota anglers. A documented public access point at Ethel 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.