Mud Lake
Kandiyohi County, Minnesota2,290 acresView mapDirections
Minnesota PCA publishes the water-quality measurements for Mud Lake. Here is what has been measured.
- Impaired · Mercury
- 14 ft max depth
- Public access
- Limited data
Mud Lake in Kandiyohi County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 5.9 ft visibility. Maximum depth: 14 ft. Surface area: 2290.4 acres.
Minnesota DNR's Targeted Survey on June 8, 2023 caught 2.75 northern pike per trap net at Mud Lake. Length samples in the latest survey that recorded them ran 9–30 inches. DNR survey details →
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 with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-15. Methodology: how these readings are compared.
What Mud Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
- Fishing13 species recorded
- Big water2,290 acres
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Mud Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, salinity / chlorides. Check local advisories before you swim.
Whether Mud 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 Mud Lake
These are the measurements Minnesota PCA publishes for Mud 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 5.9 ft. TSI 52.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 5.9ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | No reading 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. | 52 | Eutrophic OligotrophicMesotrophicEutrophicHypereutrophic |
High nutrients, frequent algae, reduced clarity
Ask about Mud Lake
Answers come straight from the public measurements and survey records on this page.
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 ↗
Minnesota DNR's Targeted Survey on June 8, 2023 caught 2.75 northern pike per trap net at Mud Lake. Length samples in the latest survey that recorded them ran 9–30 inches.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Mud Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
DNR Fisheries Survey Summary
7 surveys on file from MN DNR Fisheries. Most recent: 2023-06-08 (Targeted Survey).
7 surveys on file · most recent 2023-06-08 (Targeted Survey)
| Species | Catch rate (CPUE) | Size | Avg weight |
|---|---|---|---|
| Black Bullhead | 25.60 | 4–11 in 2023-06-08 | 0.19 lb |
| Yellow Bullhead | 13.99 | 5–10 in 2023-06-08 | 0.24 lb |
| Brown Bullhead | 11.44 | 4–9 in 2003-06-16 | 0.28 lb |
| Pumpkinseed | 8.00 | 4–7 in 2023-06-08 | 0.17 lb |
| Bluegill | 7.69 | 3–8 in 2018-05-29 | 0.21 lb |
| Northern Pike | 5.73 | 9–30 in 2023-06-08 | 1.59 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.
Black Bullhead
Yellow Bullhead
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
Lake Details
Max depth
14 ft
Average depth
3.8 ft
Surface area
2,290 acres
Shoreline
37.8 mi
Littoral zone
99%
Share shallower than 15 ft
Public access
Yes
Listed by Minnesota PCA
Recreation & Access
- Mud LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
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Stays near Mud Lake
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Follow Mud Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Mud Lake
Water Quality Trend: Improving
Based on 6 years of monitoring (2020–2025).
Water clarity
Improving6 years
Phosphorus
Improving-1.63 µg/L/yr6 years
Chlorophyll-a
Improving-1.55 µg/L/yr6 years
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
Designated uses not supporting: Cultural, Fish consumption.
Source: EPA ATTAINS assessment unit MN34-0158-02 · Official waterbody report
Nearby Lakes in Kandiyohi County
Frequently asked questions about Mud Lake
Where is Mud Lake?
- Mud Lake is a lake in Kandiyohi County, Minnesota. Its water-quality measurements are published by Minnesota PCA and shown on this page as reported.
What is the water quality of Mud Lake?
- Mud Lake in Kandiyohi County, Minnesota has water-quality measurements published by Minnesota PCA, shown here as reported. Water clarity: 5.9 ft visibility. Maximum depth: 14 ft. Surface area: 2290.4 acres.
Is Mud Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Mud Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury, salinity / chlorides. Check local advisories before you swim.
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.
What did the DNR fisheries survey find at Mud Lake?
- Minnesota DNR's Targeted Survey on June 8, 2023 caught 2.75 northern pike per trap net at Mud Lake. Length samples in the latest survey that recorded them ran 9–30 inches. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Mud Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
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.
Are there boat ramps on Mud Lake?
- Mud Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Mud Lake. Public access is listed as yes.
Can I fish at Mud Lake?
- Mud Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. 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 Mud Lake across LakeQuality
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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)
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 details from Minnesota DNR LakeFinder
Named boat-access points from the USGS National Boat Ramps inventory