Bony Lake

Bony Lake sits at the top of the Wisconsin DNR grading rubric with an A, a mark reached by the cleanest lakes in Wisconsin. The two scored sub-grades — clarity and phosphorus — track close together, so neither one is dragging the average down.

A TSI value of 38 puts Bony Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. The lake's 55 ft maximum depth is in the upper tier for Wisconsin — deep enough for cold-water fish to find refuge in summer. Bony Lake covers 190 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Among the 52 graded lakes in Bayfield County, Bony Lake sits at rank 15, above the county median.

No invasive species are currently listed at Bony Lake — the lake remains off the Wisconsin infested-waters roster. The fishery includes walleye among the lake's 6 documented species — a notable draw for Wisconsin anglers. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.