Long Lake
Clearwater County, Minnesota159 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Long Lake. Here is what has been measured.
- Oligotrophic
- 80 ft max depth
- Public access
Long Lake in Clearwater County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 20.5 ft visibility. Phosphorus: 7 µg/L. Chlorophyll-a (algae): 1.4 µg/L. Maximum depth: 80 ft. Surface area: 158.86 acres.
Minnesota DNR's Standard Survey on June 13, 2022 caught 1.33 northern pike per gill net at Long Lake. DNR survey details →
Long Lake is a 159-acre cold, clear oligotrophic lake in Clearwater County, Minnesota with a maximum depth of 80 feet. Phosphorus level is declining over recent sampling years. The lake supports 15 documented fish species including black bullhead, black crappie, and bluegill. Public access is available. Compared to the 36 other monitored lakes in Clearwater County, Long Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-12. Methodology: how these readings are compared.
What Long Lake is good for
From access and monitoring records, not editorial picks.
- Clear water20.5 ft of visibility
- Fishing15 species recorded
- Ice seasonIce-out around May 4
- Deep water80 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 20.5 ft down. Phosphorus 7 µg/L. Chlorophyll-a 1.4 µg/L. TSI 33.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 20.5ft | 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) | 1.4µg/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. | 33 | 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 58°F at the surface in September. Summer average is about 62°F. Usually warmest in Jul (about 66°F) and coldest in May (about 51°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (51°F) to its warmest (66°F).
Typical surface water temperature by month, from 164 field readings (2018–2025) via the EPA Water Quality Portal. See the full Long Lake water temperature breakdown →
Minnesota DNR's Standard Survey on June 13, 2022 caught 1.33 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 6 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
9 surveys on file from MN DNR Fisheries. Most recent: 2022-06-13 (Standard Survey).
9 surveys on file · most recent 2022-06-13 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 28.54 | 4–8 in 2022-06-13 | 0.15 lb |
| Yellow Perch | 13.22 | 5–11 in 2022-06-13 | 0.21 lb |
| Pumpkinseed | 8.14 | 3–8 in 2022-06-13 | 0.29 lb |
| Hybrid Sunfish | 7.53 | 5–8 in 2022-06-13 | 0.23 lb |
| Rock Bass | 7.03 | 5–8 in 2022-06-13 | 0.24 lb |
| Yellow Bullhead | 3.18 | 5–12 in 2022-06-13 | 0.53 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
Yellow Perch
Pumpkinseed
Hybrid Sunfish
From the 2022-06-13 survey
Long Lake is a 159-acre lake located in southern Clearwater County just west of Itasca State Park off of MN State Hwy 200. The lake is located adjacent to a county park with camping facilities. There is a public water access located in the park on the northwest end of the lake. The lake is a popular destination for…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Long Lake. 4 reports 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
- —Aquatic Plant Report — Long (1690)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — LongFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — LongPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
80 ft
Surface area
159 acres
Shoreline
3.2 mi
Littoral zone
15%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
2 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,509 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 Clearwater 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.
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Fish Species
Click a species to see every lake where it is documented.
Fishing Long Lake
Water Quality Trend: Stable
Based on 6 years of monitoring (2020–2025).
Water clarity
Stable6 years
Phosphorus
Worsening+0.43 µg/L/yr6 years
Chlorophyll-a
Improving-0.12 µg/L/yr5 years
Ice season
Typical ice-out
May 4
Earliest Apr 9, 2024 · Latest May 9, 2022
Typical ice-in
Dec 8
Earliest Nov 24, 2018 · Latest Dec 12, 2017
Most recent ice-out
Apr 9
2024
10 observations · Minnesota PCA ice records
Nearby Lakes in Clearwater County
Frequently asked questions about Long Lake
Where is Long Lake?
- Long Lake is a lake in Clearwater 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 Clearwater County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 20.5 ft visibility. Phosphorus: 7 µg/L. Chlorophyll-a (algae): 1.4 µg/L. Maximum depth: 80 ft. Surface area: 158.86 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 58°F at the surface in September, from 164 EPA Water Quality Portal field readings (2018–2025). That is a typical value for the month, not a live reading.
How deep is Long Lake?
- Long Lake has a maximum depth of 80 feet. The lake covers 158.86 acres.
What fish are in Long Lake?
- Fish species found in Long Lake include black bullhead, black crappie, bluegill, brown bullhead, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rainbow trout, rock bass, walleye, white sucker, yellow bullhead, yellow perch. Long Lake is located in Clearwater County, Minnesota.
What did the DNR fisheries survey find at Long Lake?
- Minnesota DNR's Standard Survey on June 13, 2022 caught 1.33 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 6 years of monitoring is stable. 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 May 4. Ice typically forms around Dec 8. The open water season is approximately 218 days.
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.
Explore Long Lake across LakeQuality
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Where this data comes from
153 measurements from 2 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
MNPCA153 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- Phosphorus by Colorimetry
Monitoring station identifiers (2)
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