Ann Lake

Ann Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Sherburne County. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

The lake sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. Ann Lake reaches 26 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. At 183 acres, Ann Lake fits the Minnesota median for monitored lakes, with 4.6 miles of shoreline. Within Sherburne County's 24 graded waters, Ann Lake sits at rank 6, near the top of the local distribution.

Zebra mussels have been documented at Ann Lake, which alters the filter-feeding balance and can paradoxically increase water clarity while disrupting the food web. Bass fishing is part of the appeal: the species list runs to 10, anchored by largemouth and/or smallmouth bass. A documented public access point at Ann Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.