Tulaby Lake

On the LakeGrade scale Tulaby Lake grades a B, with clarity at 7.5 ft and 24 µg/L of phosphorus placing it above the Minnesota median. 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 49 places Tulaby Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. A maximum depth of 43 ft puts Tulaby Lake in the middle of Minnesota's depth distribution. At 832 acres, Tulaby Lake fits the Minnesota median for monitored lakes, with 5.8 miles of shoreline. Tulaby Lake ranks 7 of 16 in Mahnomen County — solidly in the upper half of the local distribution.

No invasive species are currently listed at Tulaby Lake — the lake remains off the Minnesota infested-waters roster. The fishery includes walleye alongside the lake's other 16 documented species — a notable draw for Minnesota anglers. A documented public access point at Tulaby Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. Ice-out has been logged at Tulaby Lake more than two dozen times, putting the median around Apr 19 — a useful baseline for tracking climate trends. 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.