Little Thunder Lake

Little Thunder Lake earns an A — every scored parameter (clarity and phosphorus) rates among the best monitored waters in Beltrami County. 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 maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Within Beltrami County's 92 graded waters, Little Thunder Lake sits at rank 15, near the top of the local distribution.

No invasive species are currently listed at Little Thunder Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Little Thunder Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. 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.