Unnamed Lake
Big Stone County, Minnesota147 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Unnamed Lake. Here is what has been measured.
- 15 ft max depth
- Public access
- Limited data
Unnamed Lake in Big Stone County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 2 ft visibility. Phosphorus: 518.5 µg/L. Chlorophyll-a (algae): 44.4 µg/L. Maximum depth: 15 ft. Surface area: 147.21 acres.
Minnesota DNR's Standard Survey on June 5, 2023 caught 22.00 black bullhead per gill net at Unnamed Lake. Length samples in the latest survey that recorded them ran 4–10 inches. DNR survey details →
Unnamed Lake is a 147-acre lake in Big Stone County, Minnesota with a maximum depth of 15 feet. The lake supports 8 documented fish species including black bullhead, black crappie, and common carp. Public access is available.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2023-07-31. Methodology: how these readings are compared.
What Unnamed Lake is good for
From access and monitoring records, not editorial picks.
- Fishing8 species recorded
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Unnamed 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 Unnamed Lake
These are the measurements Minnesota PCA publishes for Unnamed 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 ft of visibility. Phosphorus 518.5 µg/L. Chlorophyll-a 44.4 µg/L. TSI 76.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 2ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 519µg/L | Measured, not scored The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. |
| Chlorophyll-a (algae) | 44.4µg/L | Measured, not scored 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. | 76 | Hypereutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Very high nutrients, dense algae, poor clarity
Ask about Unnamed Lake
Answers come straight from the public measurements and survey records on this page.
Minnesota DNR's Standard Survey on June 5, 2023 caught 22.00 black bullhead per gill net at Unnamed Lake. Length samples in the latest survey that recorded them ran 4–10 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Unnamed Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
15 surveys on file from MN DNR Fisheries. Most recent: 2023-06-05 (Standard Survey).
15 surveys on file · most recent 2023-06-05 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Fathead Minnow | 476.27 | ||
| Common Carp | 125.97 | 22–25 in 2023-06-05 | 1.53 lb |
| Black Bullhead | 93.12 | 4–10 in 2023-06-05 | 0.19 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.
Common Carp
Black Bullhead
From the 2023-06-05 survey
Long Tom Lake is a 133-acre reservoir located three miles east and two miles north of Ortonville in Big Stone County. The lake is primarily managed for walleyes. A fishing pier and boat launch are located on the north side of the lake. A winterkill occurred during the winter of 2018-2019 even though an aeration system…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Unnamed Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — Long TomFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — Long TomFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — Long TomPublic Water Access Sites · MN DNR LakeFinder
Lake Details
Max depth
15 ft
Surface area
147 acres
Shoreline
4.6 mi
Littoral zone
100%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
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Fish Species
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Fishing Unnamed Lake
Nearby Lakes in Big Stone County
Frequently asked questions about Unnamed Lake
Where is Unnamed Lake?
- Unnamed Lake is a lake in Big Stone County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Unnamed Lake?
- Unnamed Lake in Big Stone County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 2 ft visibility. Phosphorus: 518.5 µg/L. Chlorophyll-a (algae): 44.4 µg/L. Maximum depth: 15 ft. Surface area: 147.21 acres.
Is Unnamed Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Unnamed Lake?
- Unnamed Lake has a maximum depth of 15 feet. The lake covers 147.21 acres.
What fish are in Unnamed Lake?
- Fish species found in Unnamed Lake include black bullhead, black crappie, common carp, orangespotted sunfish, suckers, walleye, white sucker, yellow perch. Unnamed Lake is located in Big Stone County, Minnesota.
What did the DNR fisheries survey find at Unnamed Lake?
- Minnesota DNR's Standard Survey on June 5, 2023 caught 22.00 black bullhead per gill net at Unnamed Lake. Length samples in the latest survey that recorded them ran 4–10 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Unnamed Lake’s water-quality measurements separately. Catch rate is not a swim clearance and is not a weekly bite report.
Can I fish at Unnamed Lake?
- Public access to Unnamed Lake is listed as yes on the lake record. 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.
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Where this data comes from
8 measurements from 2 monitoring stations, 2022–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA8 samples · 2022–2023
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
- 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 details from Minnesota DNR LakeFinder