North Grave Lake

On the LakeGrade scale North Grave Lake grades a B, with clarity at 13.0 ft and phosphorus readings still being added placing it above the Minnesota median.

A TSI near 40 places North Grave Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. North Grave Lake reaches 39 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. North Grave Lake covers 525 acres alongside 7.7 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. North Grave Lake sits at rank 85 of 141 in Itasca County, in the lower half of the local distribution.

North Grave Lake has no invasive species recorded in Minnesota state databases as of 2024, though prevention practices still apply at all access points. The fishery includes walleye among the lake's 15 documented species — a notable draw for Minnesota anglers. Public access is available — the lake is on the Minnesota PCA public-access list. Ice-out has been recorded 11 times at North Grave Lake, with a median around Apr 23. 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.