Lady Slipper Lake
Lyon County, MinnesotaLimited DataHypereutrophic
Lady Slipper Lake grades an F: every scored parameter (clarity) rates poorly, placing it among the most stressed lakes monitored in Minnesota.
Hypereutrophic conditions mean the lake is operating at the upper end of the productivity scale, with all the bloom risk that implies. Lady Slipper Lake is a shallow lake at 11 ft maximum depth, which means it warms quickly, mixes constantly, and amplifies nutrient inputs. Lady Slipper Lake covers 286 acres alongside 4.2 miles of shoreline — a mid-sized water that supports a working fishery without being so large that conditions diverge between basins. Lady Slipper Lake sits at rank 3 of 5 in Lyon County, in the lower half of the local distribution.
No invasive species are currently listed at Lady Slipper Lake — the lake remains off the Minnesota infested-waters roster. Walleye are documented at Lady Slipper Lake, one of 6 fish species on record for the lake. A documented public access point at Lady Slipper Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-09-01. Grade methodology: LakeGrade methodology.
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Swimming Safety
Avoid swimming, very poor water quality, potential algae toxins
Water Quality Grade: F, Very Poor
Very murky, less than 1.5 ft of visibility. Trophic State Index: 71.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 1.5 ft | F |
| Phosphorus | No data | |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 71 | Hypereutrophic |
Very high nutrients, dense algae, poor clarity
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 11 ft |
| Surface Area | 286.15 acres |
| Shoreline Length | 4.2 mi |
| Littoral Zone | 100% |
| Public Access | Yes |
Fish Species
Click a species to see all Minnesota and Wisconsin lakes where it is found.
→ Best fishing times for Lady Slipper Lake (14-day solunar calendar)
→ Is it safe to eat fish from Lady Slipper Lake? (mercury & PFAS guide)
→ Lady Slipper Lake fishing regulations (limits, seasons, special rules)
Water Quality Trend: ↑ Improving
Based on 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.053 m/yr | 2 |
Location
County Ranking
Ranked #3 of 5 lakes in Lyon County
Nearby Lakes in Lyon County
More Minnesota Lake Rankings
State Parks Near Lady Slipper Lake
Other Grade F Lakes in Minnesota
DNR Fisheries Survey Summary
12 surveys on file from MN DNR Fisheries. Most recent: 2023-09-11 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Black Bullhead | 128.27 | 0.17 lb |
| Walleye | 85.39 | 1.15 lb |
| Common Carp | 21.80 | 3.11 lb |
| Yellow Perch | 21.42 | 0.22 lb |
| OSS | 7.28 | 0.04 lb |
| Bluegill | 2.96 | 0.4 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.
Black Bullhead
Walleye
Common Carp
Yellow Perch
From the 2023-09-11 survey
A targeted fall night electrofishing survey was conducted on Lady Slipper during September 11, 2023 to evaluate young of year "YOY" (fingerling sized) Walleye numbers due to a fry stocking. Three electrofishing stations were sampled for a total of 30 minutes. Clarity was poor (1.5 feet). The water temperature was 71…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Lady Slipper Lake. 3 reports on file.
- —Fisheries Lake Survey — Lady SlipperFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — Lady SlipperFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — Lady SlipperPublic Water Access Sites · MN DNR LakeFinder
EPA Impairment Status
Lady Slipper 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 MN42-0020-00 · Official waterbody report
Data Sources
Water quality data from the EPA Water Quality Portal
Impairment status from EPA ATTAINS 303(d) database
Grading methodology based on Metropolitan Council standards
Lake details from Minnesota DNR LakeFinder
Most recent sample: 2024-09-01
Monitoring stations: 2