Jasper Lake

On the LakeGrade scale Jasper Lake grades a B, with clarity at 12.0 ft and phosphorus readings still being added placing it above the Minnesota median. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

A TSI near 41 places Jasper Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. At 125 ft of maximum depth, Jasper Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. Jasper Lake covers 246 acres alongside 6.6 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Jasper Lake ranks 52 of 128 in Cook County — solidly in the upper half of the local distribution.

Jasper Lake has no invasive species recorded in Minnesota state databases as of 2021, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Jasper Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. No formal public access is documented at Jasper Lake — most use is by shoreline residents and their guests. 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.