Horseshoe Lake
Horseshoe Lake in Aitkin County, Minnesota has a water quality grade of D (Nutrient-rich). 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.
- Clarity
- 3.5 ft
- Typical in August
- 70°F
- Max depth
- 12 ft
- Area
- 240 acres
- Type
- Eutrophic
- Trend
- ↓ Declining
- Public access
- No
- Ice-out
- Apr 15
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Horseshoe Lake →
Next lake in Aitkin County
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). Water quality is graded D based on 2 sampling years through 2025. 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. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyLimited data
Based on clarity and algae grades from past sampling — we do not hold live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum
Water Quality Grade: D (Nutrient-rich)
Murky, only visible to about 3.5 ft. Phosphorus level: 40 µg/L. Chlorophyll-a: 20 µg/L. Trophic State Index: 59.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.5 ft | Not graded |
| Phosphorus | 40 µg/L | Fair |
| Chlorophyll-a (Algae) | 20 µg/L | Poor |
| Trophic State Index (TSI) | 59 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay 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 grade measures nutrients and algae, not lodging — cabins and rentals around Horseshoe Lake are listed below.
Top-rated places to stay near Horseshoe Lake
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Planning a whole trip? See where to stay at Minnesota’s top lakes →
Water Temperature
Horseshoe Lake typically sits around 70°F at the surface in August. 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.
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 →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 12 ft |
| Average Depth | 7 ft |
| Surface Area | 240 acres |
| Shoreline Length | 3.7 mi |
| Littoral Zone | 100% |
| Public Access | No |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Horseshoe Lake
DNR Fisheries Survey Summary
10 surveys on file from MN DNR Fisheries. Most recent: 2022-08-22 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 11.85 | 0.21 lb |
| GOS | 10.50 | 0.08 lb |
| Black Crappie | 10.49 | 0.23 lb |
| Yellow Perch | 9.70 | 0.1 lb |
| JND | 9.65 | — |
| Yellow Bass | 3.15 | 0.85 lb |
CPUE = catch per unit effort, averaged across surveys (excludes juvenile shoreline seining). Higher CPUE = more abundant in standardized sampling.
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
GOS
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
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.065 m/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (8 observations).
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2010-03-30 (2010) | 2023-05-03 (2023) |
Most recent ice-out: 2023-05-03
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
A Total Maximum Daily Load (TMDL) plan has been approved.
Source: EPA ATTAINS assessment unit MN01-0034-00 · Official waterbody report
County Ranking
Ranked #17 of 18 lakes in Aitkin County
Nearby Lakes With Higher Grades
Horseshoe Lake holds Grade D. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
Nearby Lakes in Aitkin County
Frequently asked questions about Horseshoe Lake
What is the water quality grade for Horseshoe Lake?
- Horseshoe Lake in Aitkin County, Minnesota has a water quality grade of D (Nutrient-rich). 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?
- Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Horseshoe Lake has a water quality grade of D (Nutrient-rich). Algae concentration (chlorophyll-a) is 20 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Horseshoe Lake?
- Horseshoe Lake typically sits around 70°F at the surface in August, 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.
When does Horseshoe Lake thaw?
- Horseshoe Lake typically has ice-out around Apr 15.
Explore Horseshoe Lake across LakeGrade
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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)
Grade thresholds from the EPA National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See how grades are calculated 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