Middle Kimball Lake

Middle Kimball Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Washburn County. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

Trophically, Middle Kimball Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. Middle Kimball Lake is unusually deep for Wisconsin at 77 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. Middle Kimball Lake is small — 96 acres alongside partial shoreline records — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Within Washburn County's 48 graded lakes, Middle Kimball Lake ranks 28 — below the local median, though not at the bottom.

Middle Kimball Lake has no invasive species recorded in Wisconsin state databases as of 2025, though prevention practices still apply at all access points. Bass fishing is part of the appeal: the species list runs to 3, anchored by largemouth and/or smallmouth bass. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.