Crystal Lake

Crystal Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Marquette 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 29 puts Crystal Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. At 60 ft of maximum depth, Crystal Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. At 119 acres, Crystal Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Crystal Lake ranks 4 of 14 in Marquette County — solidly in the upper half of the local distribution.

Eurasian watermilfoil is established at Crystal Lake, which can dampen recreational access and pressure the native plant community. Bass fishing is part of the appeal: the species list runs to 3, anchored by largemouth and/or smallmouth bass. Public access is available — the lake is on the Wisconsin DNR public-access list. 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.