Long Lake
Beltrami County, Minnesota202 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Long Lake. Here is what has been measured.
- Mesotrophic
- Impaired · Nutrients (phosphorus, nitrogen)
- 83 ft max depth
- Public access
Long Lake in Beltrami County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 10 ft visibility. Phosphorus: 17 µg/L. Chlorophyll-a (algae): 4.9 µg/L. Maximum depth: 83 ft. Surface area: 201.57 acres.
Minnesota DNR's Standard Survey on June 25, 1986 caught 5.50 northern pike per gill net at Long Lake. DNR survey details →
Long Lake is a 202-acre mesotrophic lake in Beltrami County, Minnesota with a maximum depth of 83 feet. Overall water quality is declining over recent sampling years. Limited fish-species data available. Public access is available. Compared to the 84 other monitored lakes in Beltrami County, Long Lake ranks #6 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2021-09-27. Methodology: how these readings are compared.
What Long Lake is good for
From access and monitoring records, not editorial picks.
- Clear water10 ft of visibility
- Deep water83 ft surveyed max depth
Swimming conditions
Readings onlyRecreation use not supported
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Long Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Long Lake is safe to swim in today is a call for the Minnesota Pollution Control Agency and the Minnesota DNR and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Long Lake
These are the measurements Minnesota PCA publishes for Long Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 10 ft. Phosphorus 17 µg/L. Chlorophyll-a 4.9 µg/L. TSI 45.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 10ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 17µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 4.9µg/L | Good GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 45 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Long Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Long Lake typically sits around 63°F at the surface in September. Summer average is about 72°F. Usually warmest in Jul (about 73°F) and coldest in Sep (about 63°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (63°F) to its warmest (73°F).
Typical surface water temperature by month, from 29 field readings (2019–2021) via the EPA Water Quality Portal.
Minnesota DNR's Standard Survey on June 25, 1986 caught 5.50 northern pike per gill net at Long Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Long Lake’s water-quality measurements separately, and the water-quality trend over 2 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
1 survey on file from MN DNR Fisheries. Most recent: 1986-06-25 (Standard Survey).
1 survey on file · most recent 1986-06-25 (Standard Survey)
40 years old| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 57.00 | 0.16 lb | |
| Hybrid Sunfish | 9.50 | 0.16 lb | |
| Pumpkinseed | 8.50 | 0.2 lb | |
| Northern Pike | 3.38 | 2.14 lb | |
| Yellow Perch | 2.38 | 0.21 lb | |
| White Sucker | 1.50 | 2 lb |
CPUE = catch per unit effort, fish caught per net per set in a standardised survey. It measures abundance, not size, and is not a weekly bite report.
From the 1986-06-25 survey
HIGH NORTHERN PIKE POPULATION. BECAUSE OF SEVERE DROPOFF AROUND LAKE, RELIABLE NETTING IS DIFFICULT LOCAL FISHING REPORTS INDICATE A BETTER FISH POPU- LATION THAN REVEALED THAN REVEALED BY TEST NETTING
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Long Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — BuzzleFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Buzzle (1729)Aquatic Plant Report · MN DNR LakeFinder
- —Public Water Access Sites — BuzzlePublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
83 ft
Surface area
202 acres
Shoreline
3.5 mi
Littoral zone
21%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
4 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,407 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Stays via Stay22
Stays near Long Lake
Compare lakeside cabins, hotels, and vacation rentals near Long 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.
Top-rated places to stay near Long Lake
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Follow Long Lake’s readings
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Fishing Long Lake
Water quality readings over time
2 seasons of samples on record (2020–2021). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Worsening2 years
Phosphorus
Worsening+2 µg/L/yr2 years
Chlorophyll-a
Worsening+2.3 µg/L/yr2 years
EPA Impairment Status
Long Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN04-0295-00 · Official waterbody report
Nearby Lakes in Beltrami County
Frequently asked questions about Long Lake
Where is Long Lake?
- Long Lake is a lake in Beltrami County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Long Lake?
- Long Lake in Beltrami County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 10 ft visibility. Phosphorus: 17 µg/L. Chlorophyll-a (algae): 4.9 µg/L. Maximum depth: 83 ft. Surface area: 201.57 acres.
Is Long Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Long Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Long Lake?
- Long Lake typically sits around 63°F at the surface in September, from 29 EPA Water Quality Portal field readings (2019–2021). That is a typical value for the month, not a live reading.
How deep is Long Lake?
- Long Lake has a maximum depth of 83 feet. The lake covers 201.57 acres.
What did the DNR fisheries survey find at Long Lake?
- Minnesota DNR's Standard Survey on June 25, 1986 caught 5.50 northern pike per gill net at Long Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Long Lake’s water-quality measurements separately, and the water-quality trend over 2 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
Can I fish at Long Lake?
- Public access to Long Lake is listed as yes on the lake record. Seasons, size and bag limits, and whether you need a license are set by Minnesota's fish and wildlife agency, so check its current regulations before you go.
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Where this data comes from
26 measurements from 1 monitoring station, 2020–2021. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA26 samples · 2020–2021
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from 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