Rock Lake

Rock Lake sits at the top of the Minnesota PCA grading rubric with an A, a mark reached by the cleanest lakes in Minnesota. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

A TSI near 43 places Rock Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Among the 40 graded lakes in Clearwater County, Rock Lake sits at rank 13, above the county median.

No invasive species are currently listed at Rock Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Rock Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. A documented public access point at Rock Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.