Frank Lake

On the LakeGrade rubric, Frank Lake pulls an A: clarity at 42.0 ft and phosphorus readings still being added put it in the top bracket for Wisconsin. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

A TSI value of 23 puts Frank Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. Frank Lake reaches 38 ft at its deepest point — typical for Wisconsin mid-sized lakes, with seasonal stratification but limited cold-water refuge. The lake's 147 acres and partial shoreline records put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Within Vilas County's 202 graded lakes, Frank Lake ranks 129 — below the local median, though not at the bottom.

No invasive species are currently listed at Frank Lake — the lake remains off the Wisconsin infested-waters roster. Walleye are documented at Frank Lake, one of 4 fish species on record for the lake. A documented public access point at Frank Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.