Shoal Lake

Shoal Lake sits at a C on the grading scale — not impaired, not pristine, with summer measurements that vary year to year.

A TSI near 47 places Shoal Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. A maximum depth of just 7 ft means sediment-bound phosphorus releases back into the water column whenever wind stirs the bottom — a classic shallow-lake dynamic. Shoal Lake covers 676 acres alongside 4.6 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Within the 141 graded lakes of Itasca County, Shoal Lake sits at rank 112, near the bottom of the county list.

Shoal Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Shoal Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. No formal public access is documented at Shoal Lake — most use is by shoreline residents and their guests. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.