Norris Lake

Norris Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Mahnomen County. 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.

The lake sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. 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. Among the 16 graded lakes in Mahnomen County, Norris Lake ranks 4 — in the top quartile locally.

Norris Lake has no invasive species recorded in Minnesota state databases as of 2025, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Norris 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.