Six Lake

Six 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.

The lake's low TSI puts it in oligotrophic territory — the cleanest of the four trophic classes, but also the most vulnerable to nutrient-driven shifts. The lake's 140 ft maximum depth is in the upper tier for Minnesota — deep enough for cold-water fish to find refuge in summer. Six Lake covers 197 acres alongside 3.5 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Six Lake ranks 20 of 97 in Otter Tail County, putting it in the upper tier of locally monitored lakes.

Zebra mussel presence at Six Lake means the lake's clarity numbers carry an asterisk — filtered water is not the same as nutrient-poor water. Walleye are documented at Six Lake, one of 11 fish species on record for the lake. Public access is available — the lake is on the Minnesota PCA public-access list. The lake has a partial ice record — 5 observed ice-outs, centered near Apr 21. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.