Rush Lake

Rush Lake carries a solid B grade — strong on most parameters, with measurements that hold up well across the summer season. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

At a TSI of 51, Rush Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. The lake's 68 ft maximum depth is in the upper tier for Minnesota — deep enough for cold-water fish to find refuge in summer. At 5,276 acres, Rush Lake is one of the larger lakes in Otter Tail County, with 13.6 miles of shoreline supporting multiple distinct use patterns. Within Otter Tail County's 97 graded lakes, Rush Lake ranks 72 — below the local median, though not at the bottom.

Rush 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 Rush Lake, one of 19 fish species on record for the lake. A documented public access point at Rush Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. Ice-out has been recorded 8 times at Rush Lake, with a median around Apr 14. 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.