Armour Lake

On the LakeGrade rubric, Armour Lake pulls an A: clarity at 34.5 ft and 12 µg/L of phosphorus put it in the top bracket for Wisconsin. 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.

Trophically, Armour Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. Armour Lake is unusually deep for Wisconsin at 56 ft, which buffers the lake against summer warming and helps the deep water stay oxygenated. At 328 acres, Armour Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Armour Lake sits at rank 104 of 202 in Vilas County, in the lower half of the local distribution.

Armour Lake has no invasive species recorded in Wisconsin state databases as of 2025, though prevention practices still apply at all access points. Walleye are documented at Armour Lake, one of 6 fish species on record for the lake. 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.