Boulder Lake

Boulder Lake earns a C — middle-of-the-pack water quality, with one or two parameters dragging the average down from a stronger grade. Secchi readings are the weakest of the three parameters, suggesting suspended sediment or algal biomass dominates the optical signal.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. A maximum depth of 23 ft puts Boulder Lake in the middle of Wisconsin's depth distribution. At 516 acres, Boulder Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Boulder Lake sits at rank 138 of 191 in Vilas County, in the lower half of the local distribution.

Boulder Lake has at least one documented invasive species (Banded Mystery Snail), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. Walleye are documented at Boulder Lake, one of 6 fish species on record for the lake. A documented public access point at Boulder Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. 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.