Miller Lake
Carlton County, MinnesotaEutrophic
Miller Lake earns a C — middle-of-the-pack water quality, with one or two parameters dragging the average down from a stronger grade. Secchi readings are the weakest of the three parameters, suggesting suspended sediment or algal biomass dominates the optical signal.
At a TSI of 53, Miller Lake reads as eutrophic — nutrient-rich enough that summer algal growth and reduced clarity are expected, not unusual. 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. Miller Lake sits at rank 20 of 33 in Carlton County, in the lower half of the local distribution.
No invasive species are currently listed at Miller Lake — the lake remains off the Minnesota infested-waters roster. The state fisheries records do not list documented species for Miller Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. Public access is available — the lake is on the Minnesota PCA public-access list. The grade is supported by multiple sampling years from Minnesota PCA volunteers and partner agencies, giving the letter a reasonably stable foundation.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-17. Grade methodology: LakeGrade methodology.
Swimming Safety
Generally safe for swimming, moderate water quality
Water Quality Grade: C, Fair
Very murky, less than 2 ft of visibility. Phosphorus level: 32 µg/L. Chlorophyll-a: 2.3 µg/L. Trophic State Index: 53.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2 ft | F |
| Phosphorus | 32 µg/L | C |
| Chlorophyll-a (Algae) | 2.3 µg/L | A |
| Trophic State Index (TSI) | 53 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +2.237 m/yr | 5 |
| Phosphorus | ↑ Improving | -13.5 µg/L/yr | 2 |
| Chlorophyll-a | ↓ Declining | +0.19 µg/L/yr | 6 |
Location
County Ranking
Ranked #20 of 33 lakes in Carlton County
Nearby Lakes in Carlton County
More Minnesota Lake Rankings
State Parks Near Miller Lake
Other Grade C Lakes in Minnesota
Eutrophic Lakes in Minnesota
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Miller Lake. 2 reports on file.
- —Aquatic Plant Report — Miller (0327)Aquatic Plant Report · MN DNR LakeFinder
- —Public Water Access Sites — MillerPublic Water Access Sites · MN DNR LakeFinder
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Most recent sample: 2024-10-17
Monitoring stations: 1