Shields Lake

Shields Lake earns an F: phosphorus readings still being added and clarity at 2.5 ft signal heavy nutrient loading from the surrounding watershed.

A TSI in the eutrophic range signals a lake doing what nutrient-loaded waters do — supporting an active algal community at the cost of clear water. A maximum depth of 42 ft puts Shields Lake in the middle of Minnesota's depth distribution. At 940 acres, Shields Lake fits the Minnesota median for monitored lakes, with 9.0 miles of shoreline. Within Rice County's 12 graded lakes, Shields Lake ranks 9 — below the local median, though not at the bottom.

Eurasian watermilfoil is established at Shields Lake, which can dampen recreational access and pressure the native plant community. Walleye are documented at Shields Lake, one of 17 fish species on record for the lake. Public access is available — the lake is on the Minnesota PCA public-access list. Ice-out has been logged at Shields Lake more than two dozen times, putting the median around Apr 5 — a useful baseline for tracking climate trends. 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.