West Mcdonald Lake

West Mcdonald Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Otter Tail County. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

A TSI value of 37 puts West Mcdonald Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. West Mcdonald Lake is unusually deep for Minnesota at 62 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. West Mcdonald Lake covers 597 acres alongside 4.7 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Among the 97 graded lakes in Otter Tail County, West Mcdonald Lake ranks 24 — in the top quartile locally.

Zebra mussels have been documented at West Mcdonald Lake, which alters the filter-feeding balance and can paradoxically increase water clarity while disrupting the food web. Walleye are documented at West Mcdonald Lake, one of 15 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 logged at West Mcdonald Lake more than two dozen times, putting the median around Apr 20 — a useful baseline for tracking climate trends. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.