Alma Lake

On the LakeGrade rubric, Alma Lake pulls an A: clarity at 12.0 ft and 15 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.

The lake sits in the mesotrophic zone — the band where most well-managed Wisconsin lakes fall. A maximum depth of 18 ft puts Alma Lake in the middle of Wisconsin's depth distribution. At 58 acres, Alma Lake sits below the Wisconsin median: a small water where shoreline activity has an outsized effect on water quality. Among the 191 graded lakes in Vilas County, Alma Lake sits at rank 72, above the county median.

An invasive species record — Chinese Mystery Snail — has been logged at Alma Lake; Wisconsin DNR maintains the official infested-waters list. Walleye are documented at Alma Lake, one of 5 fish species on record for the lake. A documented public access point at Alma Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.