State Line Lake
Freeborn County, Minnesota372 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for State Line Lake. Here is what has been measured.
- Impaired · Nutrients (phosphorus, nitrogen)
- 33 ft max depth
- Public access
- Limited data
State Line Lake in Freeborn County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 5.2 ft visibility. Surface area: 371.95 acres.
Minnesota DNR's Targeted Survey on September 12, 2017 caught 7.00 northern pike per trap net at State Line Lake. Length samples in the latest survey that recorded them ran 20–29 inches. DNR survey details →
State Line Lake is a 372-acre lake in Freeborn County, Minnesota with an estimated average depth of about 33 feet. The lake supports 5 documented fish species including black bullhead, bluegill, and common carp. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2022-10-01. Methodology: how these readings are compared.
What State Line Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing5 species recorded
- Ice seasonIce-out around Mar 20
Swimming conditions
No readingRecreation use not supported
Nutrient and algae readings are not a swimming clearance. State Line Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether State Line 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 State Line Lake
These are the measurements Minnesota PCA publishes for State Line Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Murky, only visible to about 5.2 ft. TSI 53.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 5.2ft | 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. | 53 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about State Line Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
State Line Lake typically sits around 66°F at the surface in September. Summer average is about 74°F. Usually warmest in Jul (about 77°F) and coldest in May (about 60°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (60°F) to its warmest (77°F).
Typical surface water temperature by month, from 12 field readings (2016–2019) via the EPA Water Quality Portal. See the full State Line Lake water temperature breakdown →
Minnesota DNR's Targeted Survey on September 12, 2017 caught 7.00 northern pike per trap net at State Line Lake. Length samples in the latest survey that recorded them ran 20–29 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows State Line Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
1 survey on file from MN DNR Fisheries. Most recent: 2017-09-12 (Targeted Survey).
1 survey on file · most recent 2017-09-12 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Black Bullhead | 212.67 | 4–13 in 2017-09-12 | 0.02 lb |
| Common Carp | 15.67 | 4–18 in 2017-09-12 | 1.74 lb |
| Northern Pike | 7.00 | 20–29 in 2017-09-12 | 3.69 lb |
| Yellow Perch | 5.33 | 7–12 in 2017-09-12 | 0.47 lb |
| Bluegill | 2.67 | 5–6 in 2017-09-12 | 0.21 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
Common Carp
Northern Pike
Yellow Perch
From the 2017-09-12 survey
State Line Lake is a 446 acre shallow lake located near the southern Minnesota border on the north side of the town of State Line in Freeborn County. It is managed cooperatively with DNR Wildlife primarily for duck hunting and secondarily for fishing. The primary management species are Northern Pike and Yellow Perch…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for State Line Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — State LineFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — State LineFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — State LinePublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
~33 ft est.
Surface area
372 acres
Shoreline
3.8 mi
Public access
Yes
Listed by Minnesota PCA
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Minnesota has not published bathymetry for State Line Lake.
Lake Size & Watershed
Watershed (drainage) area
10 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,250 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Recreation & Access
- State Line 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 State Line Lake
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Fish Species
Click a species to see every lake where it is documented.
Fishing State Line Lake
Ice season
Typical ice-out
Mar 20
Earliest Mar 12, 2016 · Latest Apr 28, 2018
Most recent ice-out
Apr 28
2018
5 observations · Minnesota PCA ice records
Reservoir Info (USACE NID)
State Line Lake is a man-made reservoir impounded by the State Line Lake (completed 1930), built primarily for fish and wildlife pond on the Winnebago River-TR; gravity-type dam, 8 ft tall and 60 ft long.
- Surface area
- 425 ac
- Normal storage
- 143 ac-ft
- Max storage
- 143 ac-ft
- Drainage area
- 10 sq mi
- Hazard class
- Low
- Owner
- County of Freeborn
Source: USACE National Inventory of Dams, NID ID MN01302 · Operator website
EPA Impairment Status
State Line 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: Recreation.
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN24-0030-00 · Official waterbody report
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of State Line Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Emmons WwtpEmmons · 1 mi away · NPDES MN0023311Recent violation
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.
Nearby Lakes in Freeborn County
Frequently asked questions about State Line Lake
Where is State Line Lake?
- State Line Lake is a lake in Freeborn County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of State Line Lake?
- State Line Lake in Freeborn County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 5.2 ft visibility. Surface area: 371.95 acres.
Is State Line Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. State Line Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
What is the water temperature of State Line Lake?
- State Line Lake typically sits around 66°F at the surface in September, from 12 EPA Water Quality Portal field readings (2016–2019). That is a typical value for the month, not a live reading.
How deep is State Line Lake?
- No published bathymetric survey covers State Line Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 33 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate. The lake covers 371.95 acres.
What fish are in State Line Lake?
- Fish species found in State Line Lake include black bullhead, bluegill, common carp, northern pike, yellow perch. State Line Lake is located in Freeborn County, Minnesota.
What did the DNR fisheries survey find at State Line Lake?
- Minnesota DNR's Targeted Survey on September 12, 2017 caught 7.00 northern pike per trap net at State Line Lake. Length samples in the latest survey that recorded them ran 20–29 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows State Line Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.
When does State Line Lake thaw?
- State Line Lake typically has ice-out around Mar 20.
Are there boat ramps on State Line Lake?
- State Line Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include State Line Lake. Public access is listed as yes.
Can I fish at State Line Lake?
- State Line 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 State Line Lake across LakeQuality
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Where this data comes from
6 measurements from 1 monitoring station, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA6 samples · 2022
Analytical methods
- Field measurement/observation, generic method
Monitoring station identifiers (1)
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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
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