Blanche Lake

On the LakeGrade rubric, Blanche Lake pulls an A: clarity at 12.5 ft and 11 µg/L of phosphorus put it in the top bracket for Minnesota. With clarity and phosphorus scored, the sub-grades cluster within a letter of each other, pointing to stable conditions rather than one specific stressor.

The lake's low TSI puts it in oligotrophic territory — the cleanest of the four trophic classes, but also the most vulnerable to nutrient-driven shifts. The lake's 64 ft maximum depth is in the upper tier for Minnesota — deep enough for cold-water fish to find refuge in summer. Blanche Lake covers 1,296 acres alongside 5.6 miles of shoreline, large enough that conditions can vary meaningfully between bays. Blanche Lake ranks 35 of 97 in Otter Tail County — solidly in the upper half of the local distribution.

Zebra mussels have been documented at Blanche Lake, which alters the filter-feeding balance and can paradoxically increase water clarity while disrupting the food web. 4 fish species are on record, with panfish making up the recreational core. A documented public access point at Blanche Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. Ice-out has been recorded 22 times at Blanche Lake, with a median around Apr 20. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.