Patten Lake

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

A TSI value of 35 puts Patten Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. The lake's 52 ft maximum depth is in the upper tier for Wisconsin — deep enough for cold-water fish to find refuge in summer. The lake's 254 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. Patten Lake ranks 16 of 39 in Florence County — solidly in the upper half of the local distribution.

Patten Lake has at least one documented invasive species (Chinese Mystery Snail), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. The fishery includes walleye alongside the lake's other 4 documented species — a notable draw for Wisconsin anglers. 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.