Swenson Lake
Swenson Lake in Beltrami County, Minnesota has a water quality grade of A (Excellent). Water clarity: 20.7 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 2 µg/L. Maximum depth: 76 ft. Surface area: 411.77 acres.
- Clarity
- 20.7 ft
- Typical in August
- 73°F
- Max depth
- 76 ft
- Area
- 412 acres
- Type
- Oligotrophic
- Trend
- → Stable
- Public access
- No
Next lake in Beltrami County
Swenson Lake is a 412-acre cold, clear oligotrophic lake in Beltrami County, Minnesota with a maximum depth of 76 feet (31-foot average). Water quality is graded A based on 2 sampling years through 2025. Phosphorus level is declining over recent sampling years. The lake supports 10 documented fish species including black crappie, bluegill, and largemouth bass. No public access — the lake is private or restricted. Compared to the 84 other monitored lakes in Beltrami County, Swenson Lake ranks #42 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-22. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLow algae
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.
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A (Excellent)
Crystal clear, you can see 20.7 ft down. Phosphorus level: 8 µg/L. Chlorophyll-a: 2 µg/L. Trophic State Index: 35.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 20.7 ft | Not graded |
| Phosphorus | 8 µg/L | Good |
| Chlorophyll-a (Algae) | 2 µg/L | Good |
| Trophic State Index (TSI) | 35 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Swenson Lake
Compare lakeside cabins, hotels, and vacation rentals near Swenson Lake in Beltrami 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.
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Water Temperature
Swenson Lake typically sits around 73°F at the surface in August. Summer average is about 73°F. Usually warmest in Jul (about 76°F) and coldest in May (about 54°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 18 field readings (2011–2021) via the EPA Water Quality Portal. See the full Swenson Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 76 ft |
| Average Depth | 31 ft |
| Surface Area | 412 acres |
| Shoreline Length | 3.6 mi |
| Littoral Zone | 33% |
| 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 Swenson Lake
DNR Fisheries Survey Summary
1 survey on file from MN DNR Fisheries. Most recent: 1993-07-19 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 31.38 | 0.17 lb |
| Largemouth Bass | 22.43 | 0.73 lb |
| Yellow Perch | 18.14 | 0.21 lb |
| Northern Pike | 7.54 | 2.91 lb |
| Rock Bass | 7.37 | 0.21 lb |
| Pumpkinseed | 5.44 | 0.21 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.
Bluegill
Largemouth Bass
Yellow Perch
Northern Pike
From the 1993-07-19 survey
The fish community of Swenson lake is diverse with most preferred species well represented. The exception to this is probably the apparent loss of a Smallmouth Bass fishery. One smallmouth was observed while scuba diving, though none were captured.The Walleye population is good with a history of consistant natural…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Swenson Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — SwensonFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — SwensonFish Stocking History · MN DNR LakeFinder
Water Quality Trend: → Stable
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.021 m/yr | 6 |
| Phosphorus | ↓ Declining | +0.4 µg/L/yr | 6 |
| Chlorophyll-a | ↑ Improving | -0.05 µg/L/yr | 6 |
EPA Impairment Status
Swenson Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN04-0085-00 · Official waterbody report
County Ranking
Ranked #42 of 85 lakes in Beltrami County
Nearby Lakes in Beltrami County
Frequently asked questions about Swenson Lake
What is the water quality grade for Swenson Lake?
- Swenson Lake in Beltrami County, Minnesota has a water quality grade of A (Excellent). Water clarity: 20.7 ft visibility. Phosphorus: 8 µg/L. Chlorophyll-a (algae): 2 µg/L. Maximum depth: 76 ft. Surface area: 411.77 acres.
Is Swenson Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Swenson Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 2 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Swenson Lake?
- Swenson Lake typically sits around 73°F at the surface in August, from 18 EPA Water Quality Portal field readings (2011–2021). That is a typical value for the month, not a live reading.
How deep is Swenson Lake?
- Swenson Lake has a maximum depth of 76 feet and an average depth of 31 feet. The lake covers 411.77 acres.
What fish are in Swenson Lake?
- Fish species found in Swenson Lake include black crappie, bluegill, largemouth bass, northern pike, pumpkinseed, rock bass, tullibee (cisco), walleye, white sucker, yellow perch. Swenson Lake is located in Beltrami County, Minnesota.
Explore Swenson Lake across LakeGrade
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Where this data comes from
80 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA80 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
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