Farm Island Lake

On the LakeGrade scale Farm Island Lake grades a B, with clarity at 10.5 ft and phosphorus readings still being added placing it above the Minnesota median.

A TSI near 43 places Farm Island Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. At 56 ft of maximum depth, Farm Island Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. With 2,005 acres of surface and 14.6 miles of shoreline, Farm Island Lake is a large water by Minnesota standards — recreational pressure is spread across a long shoreline. Farm Island Lake ranks 16 of 53 in Aitkin County — solidly in the upper half of the local distribution.

Zebra mussel presence at Farm Island Lake means the lake's clarity numbers carry an asterisk — filtered water is not the same as nutrient-poor water. Walleye are documented at Farm Island Lake, one of 17 fish species on record for the lake. A documented public access point at Farm Island Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The lake has a long ice-out record — 77 observations on file, with a median ice-out around Apr 19. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.