Sanborn Lake

Sanborn Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Vilas County. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

The lake sits in the mesotrophic zone — the band where most well-managed Wisconsin lakes fall. Sanborn Lake is a shallow lake at 13 ft maximum depth, which means it warms quickly, mixes constantly, and amplifies nutrient inputs. The lake's 243 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, Sanborn Lake ranks 151 — below the local median, though not at the bottom.

Sanborn Lake has no invasive species recorded in Wisconsin state databases as of 2022, though prevention practices still apply at all access points. The fishery is bass-led, with 3 documented species across the lake's records. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.