Four Lake
Four Lake in Lake County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 8 ft visibility. Maximum depth: 25 ft. Surface area: 610.88 acres.
- Clarity
- 8 ft
- Max depth
- 25 ft
- Area
- 611 acres
- Trend
- ↑ Improving
- Public access
- No
Next lake in Lake County
Why Four 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 Four 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.
Four Lake is a 611-acre lake in Lake County, Minnesota with a maximum depth of 25 feet. Overall water quality is improving over recent sampling years. The lake supports 9 documented fish species including bluegill, cisco species, and lake whitefish. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-03. 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 Four Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Moderate clarity, visible to about 8 ft. Trophic State Index: 47.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 8 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 47 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Four Lake
Compare lakeside cabins, hotels, and vacation rentals near Four Lake in Lake 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 Four Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 25 ft |
| Surface Area | 611 acres |
| Shoreline Length | 22.9 mi |
| Littoral Zone | 84% |
| 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 Four Lake
DNR Fisheries Survey Summary
2 surveys on file from MN DNR Fisheries. Most recent: 2017-06-19 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| White Sucker | 5.50 | 1.96 lb |
| Walleye | 4.05 | 0.71 lb |
| Northern Pike | 3.71 | 2.35 lb |
| Yellow Perch | 2.44 | 0.12 lb |
| Rock Bass | 1.15 | 0.18 lb |
| LKW | 0.93 | 1.02 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.
White Sucker
Walleye
Northern Pike
Yellow Perch
From the 2017-06-19 survey
Lake Four is located within the Boundary Waters Canoe Area Wilderness (BWCAW) within the Superior National Forest and is a non-motorized lake. It is approximately 20 miles east of Ely. It is a 611 acre lake with a maximum depth of 25 feet and has brown water. The surrounding landscape of the southern part of Lake Four…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Four Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — FourFisheries Lake Survey · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 3 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.259 m/yr | 3 |
EPA Impairment Status
Four Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN38-0528-00 · Official waterbody report
Graded lakes near Four Lake
Four Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Lake County
Frequently asked questions about Four Lake
What is the water quality grade for Four Lake?
- Four Lake in Lake County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 8 ft visibility. Maximum depth: 25 ft. Surface area: 610.88 acres.
Is Four Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Four Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
How deep is Four Lake?
- Four Lake has a maximum depth of 25 feet. The lake covers 610.88 acres.
What fish are in Four Lake?
- Fish species found in Four Lake include bluegill, cisco species, lake whitefish, northern pike, rock bass, smallmouth bass, walleye, white sucker, yellow perch. Four Lake is located in Lake County, Minnesota.
Explore Four Lake across LakeGrade
Depth, room, public access, and the state wake-sport rules
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Fish species and best lakes in Lake County
Species activity outlook by water temperature and season
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Where this data comes from
5 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
MNPCA5 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
Monitoring station identifiers (3)
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
Impairment status from EPA ATTAINS 303(d) database
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder