Craig Lake
Cass County, MinnesotaLimited DataMesotrophic
Craig Lake sits at the top of the Minnesota PCA grading rubric with an A, a mark reached by the cleanest lakes in Minnesota. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.
A TSI near 43 places Craig Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. 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. Craig Lake ranks 46 of 133 in Cass County — solidly in the upper half of the local distribution.
No invasive species are currently listed at Craig Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Craig Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. The lake lacks a documented public access point, so visitor use is limited. 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.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2019-10-08. Grade methodology: LakeGrade methodology.
Swimming Safety
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A, Excellent
No clarity data. Chlorophyll-a: 3.6 µg/L. Trophic State Index: 43.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | No data | |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | 3.6 µg/L | A |
| Trophic State Index (TSI) | 43 | Mesotrophic |
Moderate nutrients, good water quality
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.037 m/yr | 5 |
| Phosphorus | ↓ Declining | +1.2 µg/L/yr | 5 |
| Chlorophyll-a | → Stable | +0.06 µg/L/yr | 3 |
Location
County Ranking
Ranked #46 of 133 lakes in Cass County
Nearby Lakes in Cass County
More Minnesota Lake Rankings
Other Grade A Lakes in Minnesota
Mesotrophic Lakes in Minnesota
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2019-10-08
Monitoring stations: 2