Ponto Lake

On the LakeGrade rubric, Ponto Lake pulls an A: clarity at 19.0 ft and 7 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.

A TSI value of 33 puts Ponto Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. At 60 ft of maximum depth, Ponto Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. The lake's 388 acres and 4.5 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 Cass County's 133 graded waters, Ponto Lake sits at rank 22, near the top of the local distribution.

Ponto Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. Walleye are documented at Ponto Lake, one of 16 fish species on record for the lake. A documented public access point at Ponto Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. Ice-out has been logged at Ponto Lake more than two dozen times, putting the median around Apr 20 — a useful baseline for tracking climate trends. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.