Brown Lake
Brown Lake in St. Louis County, Minnesota has a water quality grade of B (Good). Water clarity: 8.5 ft visibility. Phosphorus: 17.1 µg/L. Maximum depth: 27 ft. Surface area: 72.29 acres.
- Clarity
- 8.5 ft
- Typical in August
- 64°F
- Max depth
- 27 ft
- Area
- 72 acres
- Type
- Mesotrophic
- Trend
- ↓ Declining
- Public access
- No
Next lake in St. Louis County
Brown Lake is a 72-acre mesotrophic lake in St. Louis County, Minnesota with a maximum depth of 27 feet. Water quality is graded B based on 1 sampling years through 2024. Overall water quality is declining over recent sampling years. The lake supports 2 documented fish species including northern pike and yellow perch. No public access — the lake is private or restricted. Compared to the 67 other monitored lakes in St. Louis County, Brown Lake ranks #33 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-08-27. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLimited data
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Good for swimming, clear water with low algae levels
Water Quality Grade: B (Good)
Moderate clarity, visible to about 8.5 ft. Phosphorus level: 17.1 µg/L. Trophic State Index: 46.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 8.5 ft | Not graded |
| Phosphorus | 17.1 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 46 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Brown Lake
Compare lakeside cabins, hotels, and vacation rentals near Brown 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 Brown Lake
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Water Temperature
Brown Lake typically sits around 64°F at the surface in August. Summer average is about 62°F. Usually warmest in Aug (about 64°F) and coldest in Jun (about 60°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 331 field readings (2010–2024) via the EPA Water Quality Portal. See the full Brown Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 27 ft |
| Surface Area | 72 acres |
| Shoreline Length | 2.7 mi |
| Littoral Zone | 54% |
| 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 Brown Lake
DNR Fisheries Survey Summary
2 surveys on file from MN DNR Fisheries. Most recent: 2024-07-16 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Northern Pike | 6.65 | 1.78 lb |
| Yellow Perch | 1.00 | 0.11 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.
Northern Pike
Yellow Perch
From the 2024-07-16 survey
Brown is a 76-acre, Class 10 lake in the interior of Voyageurs National Park (VNP), accessible by portage trail from Rainy Lake. Brown Lake has soft water, low fertility and low productivity. Brown Lake is 26 feet deep, and thermos stratification is common during the summer months resulting in low dissolved oxygen…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Brown Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — BrownFisheries Lake Survey · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.006 m/yr | 5 |
| Phosphorus | ↓ Declining | +2.17 µg/L/yr | 4 |
EPA Impairment Status
Brown 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 MN69-0839-00 · Official waterbody report
County Ranking
Ranked #33 of 68 lakes in St. Louis County
Nearby Lakes in St. Louis County
Frequently asked questions about Brown Lake
What is the water quality grade for Brown Lake?
- Brown Lake in St. Louis County, Minnesota has a water quality grade of B (Good). Water clarity: 8.5 ft visibility. Phosphorus: 17.1 µg/L. Maximum depth: 27 ft. Surface area: 72.29 acres.
Is Brown Lake safe to swim in?
- Good for swimming, clear water with low algae levels. Brown Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.
What is the water temperature of Brown Lake?
- Brown Lake typically sits around 64°F at the surface in August, from 331 EPA Water Quality Portal field readings (2010–2024). That is a typical value for the month, not a live reading.
How deep is Brown Lake?
- Brown Lake has a maximum depth of 27 feet. The lake covers 72.29 acres.
What fish are in Brown Lake?
- Fish species found in Brown Lake include northern pike, yellow perch. Brown Lake is located in St. Louis County, Minnesota.
Explore Brown Lake across LakeGrade
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Moderate nutrients, good water quality
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Where this data comes from
20 measurements from 1 monitoring station, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- National Park Service Water Resources Division
11NPSWRD_WQX20 samples · 2020–2024
Analytical methods
- Secchi Disk
- Alkaline Persulfate Digestion for Total N and P in Water
Monitoring station identifiers (1)
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