Long Lake
Long Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 12.5 ft visibility. Maximum depth: 33 ft. Surface area: 149.68 acres.
- Clarity
- 12.5 ft
- Typical in August
- 69°F
- Max depth
- 33 ft
- Area
- 150 acres
- Trend
- ↓ Declining
- Public access
- No
- Ice-out
- Apr 21
- Open water
- 215 days
Next lake in St. Louis County
Why Long Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Long Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Long Lake is a 150-acre lake in St. Louis County, Minnesota with a maximum depth of 33 feet. Overall water quality is declining over recent sampling years. The lake supports 8 documented fish species including black crappie, bluegill, and northern pike. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-10. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Long Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Good clarity, visible to about 12.5 ft. Trophic State Index: 41.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 12.5 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 41 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Long Lake
Compare lakeside cabins, hotels, and vacation rentals near Long Lake in St. Louis 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
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 →
Water Temperature
Long Lake typically sits around 69°F at the surface in August. Summer average is about 66°F. Usually warmest in Aug (about 69°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 62 field readings (2024–2025) via the EPA Water Quality Portal. See the full Long Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 33 ft |
| Surface Area | 150 acres |
| Shoreline Length | 4 mi |
| Littoral Zone | 51% |
| 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 Long Lake
DNR Fisheries Survey Summary
4 surveys on file from MN DNR Fisheries. Most recent: 2019-07-15 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 21.73 | 0.16 lb |
| Yellow Perch | 8.28 | 0.09 lb |
| Bluntnose Minnow | 6.67 | — |
| Black Crappie | 4.79 | 0.31 lb |
| Brown Bullhead | 4.42 | 0.7 lb |
| Northern Pike | 4.39 | 3.06 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
Yellow Perch
Black Crappie
Northern Pike
From the 2019-07-15 survey
Long Lake is located approximately 4 miles south of Eveleth near the southwest edge of the Superior National Forest. This productive lake is highly developed by area standards (120 homes and cabins in 2002) with clear water and large amounts of aquatic vegetation present. There is a private access located on Kaleva…
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
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.141 m/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (20 observations).
Estimated open water season: 215 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2021-04-07 (2021) | 2013-05-10 (2013) |
| Ice-In | 2003-11-08 (2003) | 2004-11-25 (2004) |
Most recent ice-out: 2024-04-07
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Long Lake under Clean Water Act (NPDES) discharge permits.
- Fairlane Plant/Tailings BasinEveleth · 3.6 mi away · NPDES MN0052116
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
Graded lakes near Long Lake
Long Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in St. Louis County
Frequently asked questions about Long Lake
What is the water quality grade for Long Lake?
- Long Lake in St. Louis County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 12.5 ft visibility. Maximum depth: 33 ft. Surface area: 149.68 acres.
Is Long Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Long Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
What is the water temperature of Long Lake?
- Long Lake typically sits around 69°F at the surface in August, from 62 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Long Lake?
- Long Lake has a maximum depth of 33 feet. The lake covers 149.68 acres.
What fish are in Long Lake?
- Fish species found in Long Lake include black crappie, bluegill, northern pike, pumpkinseed, rock bass, walleye, white sucker, yellow bullhead. Long Lake is located in St. Louis County, Minnesota.
When does Long Lake thaw?
- Long Lake typically has ice-out around Apr 21. Ice typically forms around Nov 22. The open water season is approximately 215 days.
Explore Long Lake across LakeGrade
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Where this data comes from
117 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
MNPCA117 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate