Clearwater Lake

On the LakeGrade rubric, Clearwater Lake pulls an A: clarity at 30.0 ft and 4 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.

The lake's low TSI puts it in oligotrophic territory — the cleanest of the four trophic classes, but also the most vulnerable to nutrient-driven shifts. The lake's 65 ft maximum depth is in the upper tier for Minnesota — deep enough for cold-water fish to find refuge in summer. The lake's 462 acres and 8.1 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Within Cook County's 128 graded waters, Clearwater Lake sits at rank 1, near the top of the local distribution.

An invasive species record — spiny waterflea — has been logged at Clearwater Lake; Minnesota PCA maintains the official infested-waters list. The state fisheries records do not list documented species for Clearwater 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.