Lake Anna

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

Trophically, Lake Anna reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. The lake's 61 ft maximum depth is in the upper tier for Wisconsin — deep enough for cold-water fish to find refuge in summer. Lake Anna is small — 33 acres alongside partial shoreline records — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Lake Anna ranks 35 of 39 in Florence County — at the lower end of the locally monitored distribution.

Lake Anna has no invasive species recorded in Wisconsin state databases as of 2023, though prevention practices still apply at all access points. The fishery is bass-led, with 3 documented species across the lake's records. Public access is available — the lake is on the Wisconsin DNR public-access list. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.