Big Pine Lake

Big Pine 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.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. At 76 ft of maximum depth, Big Pine Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. At 4,728 acres, Big Pine Lake is one of the larger lakes in Otter Tail County, with 14.6 miles of shoreline supporting multiple distinct use patterns. Big Pine Lake sits at rank 69 of 97 in Otter Tail County, in the lower half of the local distribution.

Big Pine 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 Big Pine 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 21 times at Big Pine Lake, with a median around Apr 24. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.