Island Lake

The LakeGrade rubric puts Island Lake at a C: clarity at 7.0 ft, phosphorus readings still being added, and a TSI of 49 signal an intermediate trophic state. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

Mesotrophic conditions dominate at Island Lake: enough nutrients for a healthy fishery, not so much that algal blooms become a chronic problem. Island Lake reaches 42 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. The lake's 527 acres and 7.2 miles of shoreline put it in the mid-range bucket — large enough for varied use, small enough that watershed inputs reach the whole basin. Within Pine County's 19 graded lakes, Island Lake ranks 10 — below the local median, though not at the bottom.

Island Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. Muskie are on the species list at Island Lake, alongside the lake's 13 other documented fish. Public access is available — the lake is on the Minnesota PCA public-access list. The lake has a partial ice record — 18 observed ice-outs, centered near Apr 20. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.