South Sturgeon Lake
St. Louis County, Minnesota204 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for South Sturgeon Lake. Here is what has been measured.
- Eutrophic
- 43 ft max depth
- Public access
- Limited data
South Sturgeon Lake in St. Louis County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 2.5 ft visibility. Phosphorus: 20 µg/L. Chlorophyll-a (algae): 5.9 µg/L. Maximum depth: 43 ft. Surface area: 204.44 acres.
Minnesota DNR's Standard Survey on July 18, 2016 caught 0.33 walleye per gill net at South Sturgeon Lake. DNR survey details →
South Sturgeon Lake is a 204-acre productive, nutrient-rich eutrophic lake in St. Louis County, Minnesota with a maximum depth of 43 feet. Overall water quality is declining over recent sampling years. The lake supports 10 documented fish species including black crappie, bluegill, and golden redhorse. Public access is available with 1 public boat landing. Compared to the 67 other monitored lakes in St. Louis County, South Sturgeon Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-07. Methodology: how these readings are compared.
What South Sturgeon Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing10 species recorded
- Ice seasonIce-out around Apr 21
- Deep water43 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. Check local advisories before you swim.
Whether South Sturgeon 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 Sturgeon Lake
These are the measurements Minnesota PCA publishes for South Sturgeon Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Very murky, less than 2.5 ft of visibility. Phosphorus 20 µg/L. Chlorophyll-a 5.9 µg/L. TSI 53.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 2.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 20µg/L | Good GoodFairPoor |
| Chlorophyll-a (algae) | 5.9µg/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. | 53 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about South Sturgeon Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
South Sturgeon Lake typically sits around 54°F at the surface in September. Summer average is about 55°F. Usually warmest in Jul (about 56°F) and coldest in May (about 49°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (49°F) to its warmest (56°F).
Typical surface water temperature by month, from 143 field readings (2017–2025) via the EPA Water Quality Portal. See the full South Sturgeon Lake water temperature breakdown →
Minnesota DNR's Standard Survey on July 18, 2016 caught 0.33 walleye per gill net at South Sturgeon Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows South Sturgeon Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
8 surveys on file from MN DNR Fisheries. Most recent: 2016-07-18 (Standard Survey).
8 surveys on file · most recent 2016-07-18 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Tullibee (Cisco) | 8.97 | 6–13 in 2002-07-29 | 0.66 lb |
| Bluegill | 5.11 | 3–9 in 2016-07-18 | 0.21 lb |
| Black Crappie | 1.84 | 3–11 in 2016-07-18 | 0.27 lb |
| Yellow Perch | 1.00 | 5–7 in 2016-07-18 | 0.16 lb |
| Northern Pike | 0.71 | 14–26 in 2016-07-18 | 2.67 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.
Tullibee (Cisco)
Bluegill
Black Crappie
Yellow Perch
From the 2016-07-18 survey
South Sturgeon Lake is a small, infertile lake located about 15 miles northwest of Chisholm, Minnesota. There is a public access on the southwest side of the lake. Small, accessible, infertile lakes like South Sturgeon often do not have the ability to produce high quality fisheries and are vulnerable to angling…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for South Sturgeon Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — South SturgeonFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — South Sturgeon (0831)Aquatic Plant Report · MN DNR LakeFinder
- —Public Water Access Sites — South SturgeonPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
43 ft
Surface area
204 acres
Shoreline
3.7 mi
Littoral zone
22%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
28 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,368 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- South Sturgeon LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near South Sturgeon Lake
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Top-rated places to stay near South Sturgeon Lake
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Fish Species
Click a species to see every lake where it is documented.
Fishing South Sturgeon Lake
- → South Sturgeon Lake fishing: DNR survey catch rates, species & stocking
- → South Sturgeon Lake fishing forecast & best times (species outlook + 14-day solunar calendar)
- → South Sturgeon Lake fishing regulations (limits, seasons, special rules)
- → Is it safe to eat fish from South Sturgeon Lake? (mercury & PFAS guide)
Water Quality Trend: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Worsening6 years
Phosphorus
Worsening+4.5 µg/L/yr2 years
Ice season
Typical ice-out
Apr 21
Earliest Mar 31, 2000 · Latest May 10, 1996
Typical ice-in
Nov 18
Earliest Nov 1, 2019 · Latest Nov 30, 2011
Most recent ice-out
Apr 14
2005
42 observations · Minnesota PCA ice records
Nearby Lakes in St. Louis County
Frequently asked questions about South Sturgeon Lake
Where is South Sturgeon Lake?
- South Sturgeon Lake is a lake in St. Louis 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 Sturgeon Lake?
- South Sturgeon Lake in St. Louis County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 2.5 ft visibility. Phosphorus: 20 µg/L. Chlorophyll-a (algae): 5.9 µg/L. Maximum depth: 43 ft. Surface area: 204.44 acres.
Is South Sturgeon 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 South Sturgeon Lake?
- South Sturgeon Lake typically sits around 54°F at the surface in September, from 143 EPA Water Quality Portal field readings (2017–2025). That is a typical value for the month, not a live reading.
How deep is South Sturgeon Lake?
- South Sturgeon Lake has a maximum depth of 43 feet. The lake covers 204.44 acres.
What fish are in South Sturgeon Lake?
- Fish species found in South Sturgeon Lake include black crappie, bluegill, golden redhorse, northern pike, pumpkinseed, rock bass, shorthead redhorse, walleye, white sucker, yellow perch. South Sturgeon Lake is located in St. Louis County, Minnesota.
What did the DNR fisheries survey find at South Sturgeon Lake?
- Minnesota DNR's Standard Survey on July 18, 2016 caught 0.33 walleye per gill net at South Sturgeon Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows South Sturgeon Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
When does South Sturgeon Lake thaw?
- South Sturgeon Lake typically has ice-out around Apr 21. Ice typically forms around Nov 18. The open water season is approximately 211 days.
Are there boat ramps on South Sturgeon Lake?
- South Sturgeon Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include South Sturgeon Lake. Public access is listed as yes.
Can I fish at South Sturgeon Lake?
- South Sturgeon Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. 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 Sturgeon Lake across LakeQuality
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Fish species and best lakes in St. Louis County
Species activity outlook by water temperature and season
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Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Lake Superior Basin (MN+WI), ranked by water quality
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Minnesota's cleanest lakes, ranked on agency measurements
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Where this data comes from
75 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
MNPCA75 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
- 2130 B ~ Nephelometric Method
- 2120 B ~ Color in Water by Visual Comparison
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
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate