Long Lake
Itasca County, Minnesota134 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Long Lake. Here is what has been measured.
- Oligotrophic
- Impaired · Mercury
- 85 ft max depth
- Public access
- Limited data
Long Lake in Itasca County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 16.9 ft visibility. Phosphorus: 9.5 µg/L. Chlorophyll-a (algae): 2.4 µg/L. Maximum depth: 85 ft. Surface area: 134.49 acres.
Minnesota DNR's Standard Survey on June 17, 2019 caught 8.20 northern pike per gill net at Long Lake. Length samples in the latest survey that recorded them ran 15–31 inches. DNR survey details →
Long Lake is a 134-acre cold, clear oligotrophic lake in Itasca County, Minnesota with a maximum depth of 85 feet. The lake supports 12 documented fish species including black crappie, bluegill, and bowfin (dogfish). Public access is available. Compared to the 71 other monitored lakes in Itasca County, Long Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-09-11. Methodology: how these readings are compared.
What Long Lake is good for
From access and monitoring records, not editorial picks.
- Clear water16.9 ft of visibility
- Fishing12 species recorded
- Deep water85 ft surveyed max depth
Swimming conditions
Readings onlyLimited data
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 5) for mercury. 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 16.9 ft down. Phosphorus 9.5 µg/L. Chlorophyll-a 2.4 µg/L. TSI 37.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 16.9ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 9.5µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 2.4µg/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. | 37 | 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 55°F at the surface in September. Summer average is about 56°F. Usually warmest in Aug (about 58°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 (58°F).
Typical surface water temperature by month, from 105 field readings (2024–2024) via the EPA Water Quality Portal. See the full Long Lake water temperature breakdown →
Minnesota DNR's Standard Survey on June 17, 2019 caught 8.20 northern pike per gill net at Long Lake. Length samples in the latest survey that recorded them ran 15–31 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 3 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
3 surveys on file from MN DNR Fisheries. Most recent: 2019-06-17 (Standard Survey).
3 surveys on file · most recent 2019-06-17 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 12.14 | 3–8 in 2019-06-17 | 0.18 lb |
| Northern Pike | 6.41 | 15–31 in 2019-06-17 | 1.32 lb |
| Pumpkinseed | 5.39 | 3–7 in 2019-06-17 | 0.19 lb |
| Yellow Bullhead | 2.67 | 6–11 in 2019-06-17 | 0.44 lb |
| Bowfin | 1.92 | 19–25 in 2019-06-17 | 4.48 lb |
| Brown Bullhead | 1.19 | 10–14 in 2019-06-17 | 1 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
Northern Pike
Pumpkinseed
Yellow Bullhead
From the 2019-06-17 survey
Long Lake is unique, having a distinctly large shallow basin as well as another deep, steep sided basin, creating a diversity of habitat. The shoreline has moderately low development. Northern Pike and Bluegill were listed as primary management species in the 2009 lake management plan with goals of maintaining catches…
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 — LongFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Long (0598)Aquatic Plant Report · MN DNR LakeFinder
- —Public Water Access Sites — LongPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
85 ft
Surface area
134 acres
Shoreline
3.6 mi
Littoral zone
54%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
0 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,273 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Stays via Stay22
Stays near Long Lake
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Top-rated places to stay near Long Lake
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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 readings over time
3 seasons of samples on record (2020–2024). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Stable3 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 5).
Causes of impairment
Designated uses not supporting: Fish consumption.
Source: EPA ATTAINS assessment unit MN31-0570-00 · Official waterbody report
Nearby Lakes in Itasca County
Frequently asked questions about Long Lake
Where is Long Lake?
- Long Lake is a lake in Itasca 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 Itasca County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 16.9 ft visibility. Phosphorus: 9.5 µg/L. Chlorophyll-a (algae): 2.4 µg/L. Maximum depth: 85 ft. Surface area: 134.49 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 5) for mercury. Check local advisories before you swim.
What is the water temperature of Long Lake?
- Long Lake typically sits around 55°F at the surface in September, from 105 EPA Water Quality Portal field readings (2024–2024). That is a typical value for the month, not a live reading.
How deep is Long Lake?
- Long Lake has a maximum depth of 85 feet. The lake covers 134.49 acres.
What fish are in Long Lake?
- Fish species found in Long Lake include black crappie, bluegill, bowfin (dogfish), brown bullhead, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, walleye, yellow bullhead, yellow perch. Long Lake is located in Itasca County, Minnesota.
What did the DNR fisheries survey find at Long Lake?
- Minnesota DNR's Standard Survey on June 17, 2019 caught 8.20 northern pike per gill net at Long Lake. Length samples in the latest survey that recorded them ran 15–31 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 3 years of monitoring is stable. 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
15 measurements from 1 monitoring station, 2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA15 samples · 2024
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