Round Lake

On the LakeGrade rubric, Round Lake pulls an A: clarity at 13.5 ft and 17 µg/L of phosphorus put it in the top bracket for Minnesota. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

A TSI near 42 places Round Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. Round Lake is unusually deep for Minnesota at 51 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. Round Lake covers 1,650 acres alongside 6.6 miles of shoreline, large enough that conditions can vary meaningfully between bays. Among the 120 graded lakes in Crow Wing County, Round Lake sits at rank 51, above the county median.

Zebra mussels have been documented at Round Lake, which alters the filter-feeding balance and can paradoxically increase water clarity while disrupting the food web. Round Lake's fishery is anchored by muskellunge, with 20 documented species in total — a destination water for muskie anglers. Public access is available — the lake is on the Minnesota PCA public-access list. The lake has a long ice-out record — 38 observations on file, with a median ice-out around Apr 21. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.