Chain: Middle Lake

On the LakeGrade rubric, Chain: Middle Lake pulls an A: clarity at 36.9 ft and 14 µg/L of phosphorus put it in the top bracket for Minnesota. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

A TSI value of 34 puts Chain: Middle Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. 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. Chain: Middle Lake ranks 22 of 86 in Beltrami County — solidly in the upper half of the local distribution.

Chain: Middle Lake has no invasive species recorded in Minnesota state databases as of 2025, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Chain: Middle Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.