Long Lake
Beltrami County, Minnesota412 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Long Lake. Here is what has been measured.
- Oligotrophic
- 87 ft max depth
Long Lake in Beltrami County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 20 ft visibility. Phosphorus: 7 µg/L. Chlorophyll-a (algae): 1.8 µg/L. Maximum depth: 87 ft. Surface area: 411.95 acres.
Minnesota DNR's Standard Survey on June 14, 1993 caught 3.33 walleye per gill net at Long Lake. Length samples in the latest survey that recorded them ran 7–23 inches. DNR survey details →
Long Lake is a 412-acre cold, clear oligotrophic lake in Beltrami County, Minnesota with a maximum depth of 87 feet. Overall water quality is declining over recent sampling years. The lake supports 11 documented fish species including black crappie, bluegill, and brown bullhead. No public access — the lake is private or restricted. Compared to the 84 other monitored lakes in Beltrami County, Long Lake ranks #5 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-25. Methodology: how these readings are compared.
Long Lake covers about 410 acres in Beltrami County. The median ice-out date is April 22, which is when the open-water season begins. Vrbo is where to look for cabins and lake homes around Long Lake, and Booking.com and Expedia search hotels near the lake for your dates.
What Long Lake is good for
From access and monitoring records, not editorial picks.
- Clear water20 ft of visibility
- Fishing11 species recorded
- Ice seasonIce-out around Apr 22
- Deep water87 ft surveyed max depth
Swimming conditions
Readings onlyLow algae
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. 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.
Crystal clear, you can see 20 ft down. Phosphorus 7 µg/L. Chlorophyll-a 1.8 µg/L. TSI 34.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 20ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 7µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 1.8µg/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. | 34 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about Long Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Long Lake typically sits around 66°F at the surface in October. Summer average is about 73°F. Usually warmest in Jul (about 74°F) and coldest in May (about 53°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (53°F) to its warmest (74°F).
Typical surface water temperature by month, from 38 field readings (2016–2025) via the EPA Water Quality Portal.
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Long Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was low (13,677 cells/mL) on May 9, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Minnesota DNR's Standard Survey on June 14, 1993 caught 3.33 walleye per gill net at Long Lake. Length samples in the latest survey that recorded them ran 7–23 inches.
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 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
2 surveys on file from MN DNR Fisheries. Most recent: 1993-06-14 (Standard Survey).
2 surveys on file · most recent 1993-06-14 (Standard Survey)
33 years old| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 51.06 | 1–8 in 1993-06-14 | 0.09 lb |
| Pumpkinseed | 4.99 | 4–8 in 1993-06-14 | 0.23 lb |
| Northern Pike | 4.96 | 21–35 in 1993-06-14 | 2.79 lb |
| Rock Bass | 4.31 | 3–9 in 1993-06-14 | 0.21 lb |
| Walleye | 2.73 | 7–23 in 1993-06-14 | 2.17 lb |
| White Sucker | 2.53 | 9–21 in 1993-06-14 | 2.07 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.
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
Pumpkinseed
Northern Pike
Rock Bass
From the 1993-06-14 survey
The fish community of Long Lake is in good shape and near expectations of a lake of relatively low exploitation. Northern Pike were found in good numbers and generally larger than many area lakes. The average length of pike was more than 25 inches. No small pike were captured so there may be some concern if…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Long Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — LongFisheries Lake Survey · MN DNR LakeFinder
Lake Details
Max depth
87 ft
Surface area
412 acres
Shoreline
7.7 mi
Littoral zone
44%
Share shallower than 15 ft
Public access
No
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
8 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,322 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
Prices for Oct 9–11, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Minnesota’s top lakes →
Follow Long Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Long Lake
Water Quality Trend: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Stable6 years
Phosphorus
Worsening+0.44 µg/L/yr6 years
Chlorophyll-a
Worsening+0.07 µg/L/yr6 years
Ice season
Typical ice-out
Apr 22
Earliest Apr 8, 2017 · Latest May 7, 2022
Typical ice-in
Nov 25
Earliest Apr 12, 2014 · Latest Dec 14, 2015
Most recent ice-out
Apr 23
2024
26 observations · Minnesota PCA ice records
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: 20 ft visibility. Phosphorus: 7 µg/L. Chlorophyll-a (algae): 1.8 µg/L. Maximum depth: 87 ft. Surface area: 411.95 acres.
Is Long Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Long Lake?
- Long Lake typically sits around 66°F at the surface in October, from 38 EPA Water Quality Portal field readings (2016–2025). That is a typical value for the month, not a live reading.
How deep is Long Lake?
- Long Lake has a maximum depth of 87 feet. The lake covers 411.95 acres.
What fish are in Long Lake?
- Fish species found in Long Lake include black crappie, bluegill, brown bullhead, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, walleye, white sucker, yellow perch. Long Lake is located in Beltrami County, Minnesota.
What did the DNR fisheries survey find at Long Lake?
- Minnesota DNR's Standard Survey on June 14, 1993 caught 3.33 walleye per gill net at Long Lake. Length samples in the latest survey that recorded them ran 7–23 inches. 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 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
When does Long Lake thaw?
- Long Lake typically has ice-out around Apr 22. Ice typically forms around Nov 25. The open water season is approximately 217 days.
Does Long Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Long Lake (clouds, ice, or an off-season gap). The most recent reading was low (13,677 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Can I fish at Long Lake?
- Public access to Long Lake is listed as no on the lake record, so confirm before you make the trip. 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.
Explore Long Lake across LakeQuality
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Where this data comes from
182 measurements from 3 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA182 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 (3)
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate