Tetonka Lake
Le Sueur County, Minnesota1,358 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Tetonka Lake. Here is what has been measured.
- Hypereutrophic
- Impaired · Mercury
- 2 aquatic invasives
- 35 ft max depth
- Public access
Tetonka Lake in Le Sueur County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 3 ft visibility. Phosphorus: 289 µg/L. Chlorophyll-a (algae): 48 µg/L. Maximum depth: 35 ft. Surface area: 1357.8 acres.
Minnesota DNR's Standard Survey on July 31, 2023 caught 4.75 walleye per gill net at Tetonka Lake. Length samples in the latest survey that recorded them ran 6–10 inches. DNR survey details →
Free interactive depth-contour map of Tetonka Lake, reaching a maximum surveyed depth of 30 ft. Toggle Depth contours to overlay the bathymetric survey lines. Contour data from Minnesota DNR.
Tetonka Lake is a 1,358-acre highly nutrient-loaded hypereutrophic lake in Le Sueur County, Minnesota with a maximum depth of 35 feet (19-foot average). Overall water quality is improving over recent sampling years. The lake supports 19 documented fish species including bigmouth buffalo, black bullhead, and black crappie. Public access is available with 1 public boat landing. Compared to the 12 other monitored lakes in Le Sueur County, Tetonka Lake ranks #6 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-10-07. Methodology: how these readings are compared.
Tetonka Lake covers about 1,400 acres in Le Sueur County. It has one public boat landing. The median ice-out date is April 2, which is when the open-water season begins. Vrbo is where to look for cabins and lake homes around Tetonka Lake, and Booking.com and Expedia search hotels near the lake for your dates.
What Tetonka Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing19 species recorded
- Ice seasonIce-out around Apr 2
- Deep water35 ft surveyed max depth
- Big water1,358 acres
Swimming conditions
Readings onlyRecreation use not supported
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. Tetonka Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Tetonka 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 Tetonka Lake
These are the measurements Minnesota PCA publishes for Tetonka 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 3 ft of visibility. Phosphorus 289 µg/L. Chlorophyll-a 48 µg/L. TSI 72.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 289µg/L | Poor GoodFairPoor |
| Chlorophyll-a (algae) | 48µg/L | Poor GoodFairPoor |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 72 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Tetonka Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Tetonka Lake typically sits around 72°F at the surface in September. Summer average is about 78°F. Usually warmest in Jul (about 79°F) and coldest in Sep (about 72°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (72°F) to its warmest (79°F).
Typical surface water temperature by month, from 25 field readings (2022–2023) via the EPA Water Quality Portal. See the full Tetonka Lake water temperature breakdown →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Tetonka Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (862,979 cells/mL) on July 18, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Minnesota DNR's Standard Survey on July 31, 2023 caught 4.75 walleye per gill net at Tetonka Lake. Length samples in the latest survey that recorded them ran 6–10 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Tetonka Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
19 surveys on file from MN DNR Fisheries. Most recent: 2025-10-29 (Targeted Survey).
19 surveys on file · most recent 2025-10-29 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Black Bullhead | 35.46 | 10–12 in 2023-07-31 | 0.75 lb |
| Bluegill | 16.51 | 3–8 in 2023-07-31 | 0.24 lb |
| Walleye | 14.22 | 6–10 in 2025-10-29 | 1.48 lb |
| Largemouth Bass | 13.64 | 9–15 in 2023-07-31 | 1.56 lb |
| Green Sunfish | 10.18 | 1 in 2004-07-12 | |
| Freshwater Drum | 9.00 | 11–21 in 2023-07-31 | 1.19 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.
Black Bullhead
Bluegill
Walleye
Largemouth Bass
From the 2025-10-29 survey
A survey targeting age-0 Walleye was conducted at Tetonka Lake on 29 October 2025 using 1 hour 30 minutes of standard boat electrofishing. A total of 35 age-0 Walleyes were sampled for a catch rate of 23.3/hour on-time. Catch rates during fry-stocked years (n = 15) have averaged 57.7/hour on-time while non-stocked…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Tetonka Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — TetonkaFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — TetonkaFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — TetonkaPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
35 ft
Average depth
19 ft
Surface area
1,358 acres
Shoreline
11.6 mi
Littoral zone
40%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
125 sq mi
HydroLAKES / HydroSHEDS
Elevation
994 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Tetonka 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 Tetonka Lake
Compare lakeside cabins, hotels, and vacation rentals near Tetonka Lake in Le Sueur 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. The water-quality readings cover nutrients and algae, not lodging. Cabins and rentals around Tetonka Lake are listed below.
Top-rated places to stay near Tetonka Lake
Prices for Oct 9–11, 4 adults. Change dates on the map below.
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 →
Follow Tetonka Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Tetonka Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
Water Quality Trend: Improving
Based on 6 years of monitoring (2020–2025).
Water clarity
Improving5 years
Phosphorus
Improving-178 µg/L/yr2 years
Chlorophyll-a
Improving-19.3 µg/L/yr2 years
Ice season
Typical ice-out
Apr 2
Earliest Mar 3, 2024 · Latest Apr 29, 2018
Typical ice-in
Dec 3
Earliest Nov 4, 1991 · Latest Jan 7, 2024
Most recent ice-out
Mar 26
2026
125 observations · Minnesota PCA ice records
EPA Impairment Status
Tetonka Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 4A).
Causes of impairment
Designated uses not supporting: Fish consumption, Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN40-0031-00 · Official waterbody report
Nearby Lakes in Le Sueur County
Frequently asked questions about Tetonka Lake
Where is Tetonka Lake?
- Tetonka Lake is a lake in Le Sueur County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Tetonka Lake?
- Tetonka Lake in Le Sueur County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 3 ft visibility. Phosphorus: 289 µg/L. Chlorophyll-a (algae): 48 µg/L. Maximum depth: 35 ft. Surface area: 1357.8 acres.
Is Tetonka Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Tetonka Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for mercury, nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of Tetonka Lake?
- Tetonka Lake typically sits around 72°F at the surface in September, from 25 EPA Water Quality Portal field readings (2022–2023). That is a typical value for the month, not a live reading.
How deep is Tetonka Lake?
- Tetonka Lake has a maximum depth of 35 feet and an average depth of 19 feet. The lake covers 1357.8 acres.
What fish are in Tetonka Lake?
- Fish species found in Tetonka Lake include bigmouth buffalo, black bullhead, black crappie, bluegill, bowfin (dogfish), channel catfish, common carp, freshwater drum, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, smallmouth bass, walleye, white bass, white sucker, yellow bullhead, yellow perch. Tetonka Lake is located in Le Sueur County, Minnesota.
What did the DNR fisheries survey find at Tetonka Lake?
- Minnesota DNR's Standard Survey on July 31, 2023 caught 4.75 walleye per gill net at Tetonka Lake. Length samples in the latest survey that recorded them ran 6–10 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Tetonka Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
When does Tetonka Lake thaw?
- Tetonka Lake typically has ice-out around Apr 2. Ice typically forms around Dec 3. The open water season is approximately 245 days.
Does Tetonka Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Tetonka Lake (clouds, ice, or an off-season gap). The most recent reading was high (862,979 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Are there boat ramps on Tetonka Lake?
- Tetonka Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Tetonka Lake. Public access is listed as yes.
Can I fish at Tetonka Lake?
- Tetonka 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 Tetonka Lake across LakeQuality
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Fish species and best lakes in Le Sueur County
Species activity outlook by water temperature and season
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Where this data comes from
127 measurements from 7 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
MNPCA127 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
Monitoring station identifiers (7)
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
Named boat-access points from the USGS National Boat Ramps inventory
Ice data from Minnesota DNR Climate