Deer Lake

Deer Lake comes in at a B on the grading rubric — a respectable showing for a Minnesota lake of its size and depth. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

A TSI near 45 places Deer Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. A maximum depth of 26 ft puts Deer Lake in the middle of Minnesota's depth distribution. The lake's 447 acres and 3.9 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Deer Lake ranks 47 of 97 in Otter Tail County — solidly in the upper half of the local distribution.

Zebra mussel presence at Deer Lake means the lake's clarity numbers carry an asterisk — filtered water is not the same as nutrient-poor water. The fishery includes walleye alongside the lake's other 16 documented species — a notable draw for Minnesota anglers. Public access is available — the lake is on the Minnesota PCA public-access list. The lake has a partial ice record — 8 observed ice-outs, centered near Apr 20. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.