Owl Lake

On the LakeGrade scale Owl Lake grades a B, with clarity at 13.0 ft and phosphorus readings still being added placing it above the Minnesota median.

A TSI near 40 places Owl Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. The lake's 70 ft maximum depth is in the upper tier for Minnesota — deep enough for cold-water fish to find refuge in summer. The lake is compact at 77 acres, with 2.6 miles of shoreline and little volume to buffer nutrient inputs. Among the 128 graded lakes in Cook County, Owl Lake sits at rank 46, above the county median.

Owl Lake has no invasive species recorded in Minnesota state databases as of 2022, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Owl Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. The lake lacks a documented public access point, so visitor use is limited. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.