Horseshoe Lake
Aitkin County, Minnesota240 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Horseshoe Lake. Here is what has been measured.
- Eutrophic
- Impaired · Nutrients (phosphorus, nitrogen)
- 12 ft max depth
- Limited data
Horseshoe Lake in Aitkin County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 3.5 ft visibility. Phosphorus: 40 µg/L. Chlorophyll-a (algae): 20 µg/L. Maximum depth: 12 ft. Surface area: 240.06 acres.
Minnesota DNR's Standard Survey on August 22, 2022 caught 2.00 walleye per gill net at Horseshoe Lake. DNR survey details →
Horseshoe Lake is a 240-acre productive, nutrient-rich eutrophic lake in Aitkin County, Minnesota with a maximum depth of 12 feet (7-foot average). Overall water quality is declining over recent sampling years. The lake supports 12 documented fish species including black bullhead, black crappie, and bluegill. No public access — the lake is private or restricted. Compared to the 17 other monitored lakes in Aitkin County, Horseshoe Lake ranks #17 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-28. Methodology: how these readings are compared.
What Horseshoe Lake is good for
From access and monitoring records, not editorial picks.
- Fishing12 species recorded
- Ice seasonIce-out around Apr 15
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. Horseshoe Lake is listed impaired under Clean Water Act §303(d) (IR 4A) for nutrients (phosphorus, nitrogen). Check local advisories before you swim.
Whether Horseshoe 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 Horseshoe Lake
These are the measurements Minnesota PCA publishes for Horseshoe 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 3.5 ft. Phosphorus 40 µg/L. Chlorophyll-a 20 µg/L. TSI 59.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 3.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 40µg/L | Fair GoodFairPoor |
| Chlorophyll-a (algae) | 20µg/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. | 59 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Horseshoe Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Horseshoe Lake typically sits around 65°F at the surface in September. Summer average is about 69°F. Usually warmest in Jul (about 71°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 (71°F).
Typical surface water temperature by month, from 52 field readings (2011–2025) via the EPA Water Quality Portal. See the full Horseshoe Lake water temperature breakdown →
Minnesota DNR's Standard Survey on August 22, 2022 caught 2.00 walleye per gill net at Horseshoe Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Horseshoe 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
10 surveys on file from MN DNR Fisheries. Most recent: 2022-08-22 (Standard Survey).
10 surveys on file · most recent 2022-08-22 (Standard Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Bluegill | 11.85 | 3–9 in 2022-08-22 | 0.21 lb |
| Golden Shiner | 10.50 | 6 in 2009-08-24 | 0.08 lb |
| Black Crappie | 10.49 | 4–11 in 2022-08-22 | 0.23 lb |
| Yellow Perch | 9.70 | 5–7 in 2022-08-22 | 0.1 lb |
| Yellow Bullhead | 3.15 | 7–14 in 2022-08-22 | 0.85 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.
Bluegill
Golden Shiner
Black Crappie
Yellow Perch
From the 2022-08-22 survey
Horseshoe Lake is a 237-acre lake located in northeastern Aitkin County approximately 9 miles northeast of McGregor. The lake is shallow with a maximum depth of only 12 ft. and summer algal blooms are relatively common. The water is a tannin stained dark brown in color, limiting the secchi disk reading to only 1.5 ft.…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Horseshoe Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — HorseshoeFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Horseshoe (0138)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — HorseshoeFish Stocking History · MN DNR LakeFinder
Lake Details
Max depth
12 ft
Average depth
7 ft
Surface area
240 acres
Shoreline
3.7 mi
Littoral zone
100%
Share shallower than 15 ft
Public access
No
Listed by Minnesota PCA
Lake Size & Watershed
Watershed (drainage) area
9 sq mi
HydroLAKES / HydroSHEDS
Elevation
1,214 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Stays via Stay22
Stays near Horseshoe Lake
Compare lakeside cabins, hotels, and vacation rentals near Horseshoe Lake in Aitkin 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 Horseshoe Lake are listed below.
Top-rated places to stay near Horseshoe 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 Horseshoe Lake’s readings
Email me when new measurements post for this lake. Updates stay free.
Or email
Fish Species
Click a species to see every lake where it is documented.
Fishing Horseshoe Lake
Water Quality Trend: Worsening
Based on 6 years of monitoring (2020–2025).
Water clarity
Worsening6 years
Ice season
Typical ice-out
Apr 15
Earliest Mar 30, 2010 · Latest May 3, 2023
Most recent ice-out
May 3
2023
8 observations · Minnesota PCA ice records
EPA Impairment Status
Horseshoe 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 MN01-0034-00 · Official waterbody report
Nearby Lakes in Aitkin County
Frequently asked questions about Horseshoe Lake
Where is Horseshoe Lake?
- Horseshoe Lake is a lake in Aitkin County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Horseshoe Lake?
- Horseshoe Lake in Aitkin County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 3.5 ft visibility. Phosphorus: 40 µg/L. Chlorophyll-a (algae): 20 µg/L. Maximum depth: 12 ft. Surface area: 240.06 acres.
Is Horseshoe Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Horseshoe 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 Horseshoe Lake?
- Horseshoe Lake typically sits around 65°F at the surface in September, from 52 EPA Water Quality Portal field readings (2011–2025). That is a typical value for the month, not a live reading.
How deep is Horseshoe Lake?
- Horseshoe Lake has a maximum depth of 12 feet and an average depth of 7 feet. The lake covers 240.06 acres.
What fish are in Horseshoe Lake?
- Fish species found in Horseshoe Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, walleye, yellow bullhead, yellow perch. Horseshoe Lake is located in Aitkin County, Minnesota.
What did the DNR fisheries survey find at Horseshoe Lake?
- Minnesota DNR's Standard Survey on August 22, 2022 caught 2.00 walleye per gill net at Horseshoe Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Horseshoe 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 Horseshoe Lake thaw?
- Horseshoe Lake typically has ice-out around Apr 15.
Can I fish at Horseshoe Lake?
- Public access to Horseshoe 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 Horseshoe Lake across LakeQuality
Fish species and the cleanest lakes across Minnesota
Fish species and best lakes in Aitkin County
Species activity outlook by water temperature and season
Top lakes and where to stay in the Brainerd Lakes area
Top lakes and where to stay in the Mille Lacs Area area
Where to stay at Minnesota's top lakes, each with its readings
Lakes in the Rum River Watershed, ranked by water quality
Lakes in the Pine River Watersheds (Brainerd Lakes), ranked by water quality
Minnesota's cleanest lakes, ranked on agency measurements
More lakes in Minnesota
State Parks Near Horseshoe Lake
Other Lakes in Minnesota
Eutrophic Lakes in Minnesota
Where this data comes from
97 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA97 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate