South Lake
Cook County, Minnesota1,145 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for South Lake. Here is what has been measured.
- 140 ft max depth
- Limited data
South Lake in Cook County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 26 ft visibility. Maximum depth: 140 ft. Surface area: 1144.75 acres.
Minnesota DNR's Standard Survey on June 20, 2023 caught 2.50 smallmouth bass per gill net at South Lake. Length samples in the latest survey that recorded them ran 10–16 inches. DNR survey details →
South Lake is a 1,145-acre lake in Cook County, Minnesota with a maximum depth of 140 feet. Overall water quality is improving over recent sampling years. The lake supports 6 documented fish species including brook trout, burbot, and lake trout. No public access — the lake is private or restricted.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-07-03. Methodology: how these readings are compared.
What South Lake is good for
From access and monitoring records, not editorial picks.
- Clear water26 ft of visibility
- Fishing6 species recorded
- Deep water140 ft surveyed max depth
- Big water1,145 acres
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether South 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 South Lake
These are the measurements Minnesota PCA publishes for South 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 26 ft down. TSI 30.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 26ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 30 | Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Low nutrients, clear water. No reading is a swimming clearance.
Ask about South Lake
Answers come straight from the public measurements and survey records on this page.
Minnesota DNR's Standard Survey on June 20, 2023 caught 2.50 smallmouth bass per gill net at South Lake. Length samples in the latest survey that recorded them ran 10–16 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows South Lake’s water-quality measurements separately, and the water-quality trend over 2 years of monitoring is improving. 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: 2023-06-20 (Standard Survey).
2 surveys on file · most recent 2023-06-20 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| White Sucker | 10.09 | 9–22 in 2023-06-20 | 2.16 lb |
| Tullibee (Cisco) | 5.56 | 8–10 in 2023-06-20 | 0.19 lb |
| Lake Trout | 4.63 | 11–31 in 2023-06-20 | 3.52 lb |
| Smallmouth Bass | 2.83 | 10–16 in 2023-06-20 | 1.14 lb |
| Yellow Perch | 0.83 | 0.07 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.
White Sucker
Tullibee (Cisco)
Lake Trout
Smallmouth Bass
From the 2023-06-20 survey
South Lake lies on the Minnesota-Ontario border. The Minnesota side is entirely inside the BWCAW and has been non-motorized since 1978. There are no restrictions on motorized use on the Ontario side of the lake. Access is provided by portage trails from North, Topper, and Rose (via Rat) Lakes. Public access is…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for South Lake. 1 report on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — SouthFisheries Lake Survey · MN DNR LakeFinder
Lake Details
Max depth
140 ft
Surface area
1,145 acres
Shoreline
15 mi
Littoral zone
15%
Share shallower than 15 ft
Public access
No
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
17 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,545 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Stays via Stay22
Stays near South Lake
Compare lakeside cabins, hotels, and vacation rentals near South Lake in Cook 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 South Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Follow South Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing South Lake
Water quality readings over time
2 seasons of samples on record (2023–2025). Calling a direction takes at least 4 years of the same measurement.
Water clarity
Improving2 years
Nearby Lakes in Cook County
Frequently asked questions about South Lake
Where is South Lake?
- South Lake is a lake in Cook County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of South Lake?
- South Lake in Cook County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 26 ft visibility. Maximum depth: 140 ft. Surface area: 1144.75 acres.
Is South Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is South Lake?
- South Lake has a maximum depth of 140 feet. The lake covers 1144.75 acres.
What fish are in South Lake?
- Fish species found in South Lake include brook trout, burbot, lake trout, smallmouth bass, tullibee (cisco), white sucker. South Lake is located in Cook County, Minnesota.
What did the DNR fisheries survey find at South Lake?
- Minnesota DNR's Standard Survey on June 20, 2023 caught 2.50 smallmouth bass per gill net at South Lake. Length samples in the latest survey that recorded them ran 10–16 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows South Lake’s water-quality measurements separately, and the water-quality trend over 2 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
Can I fish at South Lake?
- Public access to South 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 South Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Cook County
Species activity outlook by water temperature and season
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Lake Superior Basin (MN+WI), ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
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Other Lakes in Minnesota
Oligotrophic Lakes in Minnesota
Where this data comes from
3 measurements from 2 monitoring stations, 2023–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA3 samples · 2023–2025
Analytical methods
- Field measurement/observation, generic method
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