Stoney Lake

On the LakeGrade rubric, Stoney Lake pulls an A: clarity at 19.0 ft and 13 µg/L of phosphorus put it in the top bracket for Minnesota. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

A TSI value of 38 puts Stoney Lake in the oligotrophic range, where biological productivity stays low and the water column remains clear. At 58 ft of maximum depth, Stoney Lake stratifies reliably through the summer — the hypolimnion stays cooler and clearer than the surface layer suggests. At 87 acres, Stoney Lake sits below the Minnesota median: a small water where shoreline activity has an outsized effect on water quality. Among the 51 graded lakes in Douglas County, Stoney Lake sits at rank 13, above the county median.

Stoney Lake is on the Minnesota infested-waters list for zebra mussels — boaters should follow clean-drain-dry protocols when moving gear to or from the lake. The fishery includes walleye alongside the lake's other 10 documented species — a notable draw for Minnesota anglers. The lake lacks a documented public access point, so visitor use is limited. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.