Sugar Lake

Sugar Lake comes in at a B on the grading rubric — a respectable showing for a Minnesota lake of its size and depth. The lake's weakest score is on Secchi depth — the water looks more turbid than its phosphorus number alone would predict.

A TSI near 46 places Sugar Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. A maximum depth of 22 ft puts Sugar Lake in the middle of Minnesota's depth distribution. With 1,509 acres of surface and 6.1 miles of shoreline, Sugar Lake is a large water by Minnesota standards — recreational pressure is spread across a long shoreline. Sugar Lake ranks 59 of 141 in Itasca County — solidly in the upper half of the local distribution.

Zebra mussels have been documented at Sugar Lake, which alters the filter-feeding balance and can paradoxically increase water clarity while disrupting the food web. Walleye are documented at Sugar Lake, one of 13 fish species on record for the lake. No formal public access is documented at Sugar Lake — most use is by shoreline residents and their guests. The grade is supported by multiple sampling years from Minnesota PCA volunteers and partner agencies, giving the letter a reasonably stable foundation.