Deep Lake

Deep Lake carries a solid B grade — strong on most parameters, with measurements that hold up well across the summer season. The lake's weakest score is on Secchi depth — the water looks more turbid than its phosphorus number alone would predict.

A TSI near 46 places Deep Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. A maximum depth of 25 ft puts Deep Lake in the middle of Wisconsin's depth distribution. Deep Lake is small — 43 acres alongside partial shoreline records — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Among the 47 graded lakes in Washburn County, Deep Lake sits at rank 22, above the county median.

Deep Lake has no invasive species recorded in Wisconsin state databases as of 2025, though prevention practices still apply at all access points. The fishery includes walleye alongside the lake's other 4 documented species — a notable draw for Wisconsin anglers. A documented public access point at Deep 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.