Island Lake

On the LakeGrade rubric, Island Lake pulls an A: clarity at 23.0 ft and 22 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.

A TSI near 40 places Island Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. A maximum depth of 26 ft puts Island Lake in the middle of Wisconsin's depth distribution. Island Lake covers 305 acres alongside partial shoreline records — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within Oneida County's 140 graded lakes, Island Lake ranks 90 — below the local median, though not at the bottom.

Island Lake has at least one documented invasive species (Chinese Mystery Snail), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. Walleye are documented at Island Lake, one of 6 fish species on record for the lake. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.