Oak Lake

Oak Lake pulls a D on the LakeGrade rubric — phosphorus loading and limited clarity hold it below the Minnesota average.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. A maximum depth of 20 ft puts Oak Lake in the middle of Minnesota's depth distribution. The lake's 459 acres and 4.8 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Oak Lake ranks 15 of 19 in Pine County — at the lower end of the locally monitored distribution.

No invasive species are currently listed at Oak Lake — the lake remains off the Minnesota infested-waters roster. Walleye are documented at Oak Lake, one of 12 fish species on record for the lake. A documented public access point at Oak 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.