Turtle Lake

Turtle Lake carries a solid B grade — strong on most parameters, with measurements that hold up well across the summer season. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

A TSI near 43 places Turtle Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. A maximum depth of 21 ft puts Turtle Lake in the middle of Minnesota's depth distribution. Turtle Lake covers 218 acres alongside 3.1 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Turtle Lake sits at rank 26 of 51 in Douglas County, in the lower half of the local distribution.

Zebra mussels have been documented at Turtle 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 12 documented species — a notable draw for Minnesota anglers. A documented public access point at Turtle 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.