Namakan Lake
Namakan Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 11.5 ft visibility. Maximum depth: 150 ft. Surface area: 24066.28 acres.
- Clarity
- 11.5 ft
- Max depth
- 150 ft
- Area
- 24,066 acres
- Trend
- → Stable
- Public access
- No
- Ice-out
- Apr 29
Next lake in St. Louis County
Why Namakan Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Namakan Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Namakan Lake is a 24,066-acre lake in St. Louis County, Minnesota with a maximum depth of 150 feet (45-foot average). The lake supports 18 documented fish species including black bullhead, black crappie, and bluegill. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2023-08-22. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Namakan Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Good clarity, visible to about 11.5 ft. Trophic State Index: 42.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 11.5 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 42 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Namakan Lake
Compare lakeside cabins, hotels, and vacation rentals near Namakan Lake in St. Louis County, Minnesota — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.
Top-rated places to stay near Namakan Lake
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Namakan Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (346,737 cells/mL) on November 15, 2025.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 150 ft |
| Average Depth | 44.5 ft |
| Surface Area | 24,066 acres |
| Shoreline Length | 319.9 mi |
| Littoral Zone | 21% |
| Public Access | No |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Namakan Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
DNR Fisheries Survey Summary
42 surveys on file from MN DNR Fisheries. Most recent: 2025-09-22 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Tullibee (Cisco) | 10.60 | 0.78 lb |
| CIS | 10.21 | 0.94 lb |
| Walleye | 7.41 | 0.89 lb |
| Yellow Perch | 5.67 | 0.16 lb |
| TRP | 2.85 | 0.01 lb |
| SAR | 2.27 | 0.28 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
Length Distributions
Number of fish caught at each inch class in the most recent survey that recorded lengths. Red dashed line marks an approximate trophy threshold for that species.
Tullibee (Cisco)
CIS
Walleye
Yellow Perch
From the 2025-09-22 survey
Namakan Lake is a class 2 lake located on the Minnesota-Ontario border within Voyageurs National Park (VNP). The total surface area is 24,066 acres, of which 49% or 11,755 acres lie within Minnesota. Namakan Lake is typical of lakes within the Canadian Shield with soft, oligotrophic water and intermediate…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Namakan Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — NamakanFisheries Lake Survey · MN DNR LakeFinder
Water Quality Trend: → Stable
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | 0 m/yr | 2 |
Ice Season
Historical ice data from Minnesota DNR (5 observations).
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2012-04-01 (2012) | 2014-05-14 (2014) |
| Ice-In | 2024-01-04 (2024) | 2024-01-04 (2024) |
Most recent ice-out: 2019-04-30
EPA Impairment Status
Namakan Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MN69-0693-00 · Official waterbody report
Graded lakes near Namakan Lake
Namakan Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in St. Louis County
Frequently asked questions about Namakan Lake
What is the water quality grade for Namakan Lake?
- Namakan Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 11.5 ft visibility. Maximum depth: 150 ft. Surface area: 24066.28 acres.
Is Namakan Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Namakan Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
How deep is Namakan Lake?
- Namakan Lake has a maximum depth of 150 feet and an average depth of 44.5 feet. The lake covers 24066.28 acres.
What fish are in Namakan Lake?
- Fish species found in Namakan Lake include black bullhead, black crappie, bluegill, burbot, cisco species, lake sturgeon, lake trout, lake whitefish, northern pike, pumpkinseed, rainbow smelt, redhorse, rock bass, sauger, smallmouth bass, walleye, white sucker, yellow perch. Namakan Lake is located in St. Louis County, Minnesota.
When does Namakan Lake thaw?
- Namakan Lake typically has ice-out around Apr 29.
Does Namakan Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Namakan Lake (clouds, ice, or an off-season gap). The most recent reading was high (346,737 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Explore Namakan Lake across LakeGrade
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Where this data comes from
9 measurements from 4 monitoring stations, 2020–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA6 samples · 2020–2021 - USGS Minnesota Water Science Center
USGS-MN3 samples · 2023
Analytical methods
- Field measurement/observation, generic method
Monitoring station identifiers (4)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated and data sources.
Other records on this page
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate