Mud Lake
Mud Lake in Kandiyohi County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 5.9 ft visibility. Maximum depth: 14 ft. Surface area: 2290.4 acres.
- Clarity
- 5.9 ft
- Max depth
- 14 ft
- Area
- 2,290 acres
- Trend
- ↑ Improving
- Public access
- Yes
Next lake in Kandiyohi County
Why Mud Lake has no grade
We grade a lake only when its monitoring record clears the evidence bar: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Mud Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by MPCA and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Mud Lake is a 2,290-acre lake in Kandiyohi County, Minnesota with a maximum depth of 14 feet (4-foot average). Overall water quality is improving over recent sampling years. The lake supports 13 documented fish species including black bullhead, black crappie, and bluegill. Public access is available.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-15. Grade methodology: LakeGrade methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Mud Lake
These readings exist but do not meet the evidence bar for an A–F grade — see why.
Murky, only visible to about 5.9 ft. Trophic State Index: 52.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 5.9 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 52 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Mud Lake
Compare lakeside cabins, hotels, and vacation rentals near Mud Lake in Kandiyohi 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.
Top-rated places to stay near Mud Lake
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Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Mud Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (235,505 cells/mL) on November 29, 2025.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 14 ft |
| Average Depth | 3.8 ft |
| Surface Area | 2,290 acres |
| Shoreline Length | 37.8 mi |
| Littoral Zone | 99% |
| Public Access | Yes |
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Mud Lake
DNR Fisheries Survey Summary
7 surveys on file from MN DNR Fisheries. Most recent: 2023-06-08 (Targeted Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Black Bullhead | 25.60 | 0.19 lb |
| Yellow Bass | 13.99 | 0.24 lb |
| Brown Bullhead | 11.44 | 0.28 lb |
| Pumpkinseed | 8.00 | 0.17 lb |
| Bluegill | 7.69 | 0.21 lb |
| Northern Pike | 5.73 | 1.59 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
Yellow Bass
Brown Bullhead
Pumpkinseed
From the 2023-06-08 survey
A targeted trapnet survey of Middle Fork Crow Reservoir "MFCR", also known as Monongalia or Mud Lake, was conducted in early June of 2023. The purpose of the survey was to determine the extent of a partial winterkill in February/March of 2023. Four lake survey trapnets were set at standard stations. At least one…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Mud Lake. 4 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — Lake MonongaliaFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Lake Monongalia (0848)Aquatic Plant Report · MN DNR LakeFinder
- —Fish Stocking History — Lake MonongaliaFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — Lake MonongaliaPublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.064 m/yr | 6 |
| Phosphorus | ↑ Improving | -1.63 µg/L/yr | 6 |
| Chlorophyll-a | ↑ Improving | -1.55 µg/L/yr | 6 |
EPA Impairment Status
Mud Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit MN34-0158-02 · Official waterbody report · Matched by proximity (1 km)
Graded lakes near Mud Lake
Mud Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Kandiyohi County
Frequently asked questions about Mud Lake
What is the water quality grade for Mud Lake?
- Mud Lake in Kandiyohi County, Minnesota is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 5.9 ft visibility. Maximum depth: 14 ft. Surface area: 2290.4 acres.
Is Mud Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Mud Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
How deep is Mud Lake?
- Mud Lake has a maximum depth of 14 feet and an average depth of 3.8 feet. The lake covers 2290.4 acres.
What fish are in Mud Lake?
- Fish species found in Mud Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), common carp, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, walleye, white sucker, yellow bullhead, yellow perch. Mud Lake is located in Kandiyohi County, Minnesota.
Does Mud Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Mud Lake (clouds, ice, or an off-season gap). The most recent reading was high (235,505 cells/mL). Blue-green algae can appear and clear within days, so check Minnesota's current advisory before swimming.
Explore Mud Lake across LakeGrade
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Where this data comes from
22 measurements from 3 monitoring stations, 2024–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA22 samples · 2024–2025
Analytical methods
- Field measurement/observation, generic method
Monitoring station identifiers (3)
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