Turtle River Lake

On the LakeGrade scale Turtle River Lake grades a B, with clarity at 8.7 ft and 20 µg/L of phosphorus placing it above the Minnesota median. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

A TSI near 47 places Turtle River Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. At 63 ft of maximum depth, Turtle River Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. With 1,740 acres of surface and 17.3 miles of shoreline, Turtle River Lake is a large water by Minnesota standards — recreational pressure is spread across a long shoreline. Turtle River Lake ranks 66 of 86 in Beltrami County — at the lower end of the locally monitored distribution.

Turtle River 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 Turtle River Lake, one of 20 fish species on record for the lake. Public access is available — the lake is on the Minnesota PCA public-access list. Ice-out has been recorded 17 times at Turtle River Lake, with a median around Apr 22. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.