Mud Lake
Mud Lake in Becker County, Minnesota has a water quality grade of A (Excellent). Water clarity: 12.5 ft visibility. Phosphorus: 22 µg/L. Chlorophyll-a (algae): 5.9 µg/L. Maximum depth: 34 ft. Surface area: 1177.84 acres.
- Clarity
- 12.5 ft
- Typical in August
- 66°F
- Max depth
- 34 ft
- Area
- 1,178 acres
- Type
- Mesotrophic
- Trend
- ↓ Declining
- Public access
- Yes
- Ice-out
- Apr 24
- Open water
- 214 days
Next lake in Becker County
Mud Lake is a 1,178-acre mesotrophic lake in Becker County, Minnesota with a maximum depth of 34 feet. Water quality is graded A based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 16 documented fish species including black bullhead, black crappie, and bluegill. Public access is available. Compared to the 83 other monitored lakes in Becker County, Mud Lake ranks #2 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2025-09-26. Grade methodology: LakeGrade methodology.
Watch Mud Lake water quality
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Mud Lake Water Quality Report Card (2026)
A printable one-page report card for Mud Lake: grade, clarity, phosphorus, algae, multi-year trend, depth, and fish — with sources.
Swimming Safety
Grade onlyLow algae
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.
Excellent for swimming, crystal clear water with minimal algae
Water Quality Grade: A (Excellent)
Good clarity, visible to about 12.5 ft. Phosphorus level: 22 µg/L. Chlorophyll-a: 5.9 µg/L. Trophic State Index: 46.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 12.5 ft | Not graded |
| Phosphorus | 22 µg/L | Good |
| Chlorophyll-a (Algae) | 5.9 µg/L | Good |
| Trophic State Index (TSI) | 46 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Mud Lake
Compare lakeside cabins, hotels, and vacation rentals near Mud Lake in Becker 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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Current Conditions
USGS snapshot Jul 6, 2026, 4:30 AM from gauge 05049900 (Mud Lake North of 670th Street Near Wheaton, MN). Station page ↗ — a live reading replaces this snapshot when the gauge responds. Missing live data is not an all-clear.
Water Temperature
Mud Lake typically sits around 66°F at the surface in August. Summer average is about 65°F. Usually warmest in Jul (about 67°F) and coldest in Apr (about 48°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 839 field readings (2010–2025) via the EPA Water Quality Portal. See the full Mud Lake water temperature breakdown →
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 low (14,060 cells/mL) on April 18, 2026.
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 | 34 ft |
| Surface Area | 1,178 acres |
| Shoreline Length | 9.7 mi |
| Littoral Zone | 73% |
| Public Access | Yes |
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 Mud Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
DNR Fisheries Survey Summary
12 surveys on file from MN DNR Fisheries. Most recent: 2021-06-21 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| BNS | 217.31 | — |
| Bluntnose Minnow | 82.96 | — |
| Fathead Minnow | 66.65 | — |
| MMS | 49.09 | — |
| BKF | 38.26 | — |
| Bluegill | 27.16 | 0.2 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
From the 2021-06-21 survey
Floyd (a.k.a., Big Floyd) Lake is a 1,212-acre lake located in Becker County two miles north of the city of Detroit Lakes. Floyd Lake's shoreline is heavily developed, and the lake receives a high amount of angling pressure and recreational use. Floyd Lake consists of two basins, the shallow larger main basin and the…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Mud Lake. 3 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — FloydFisheries Lake Survey · MN DNR LakeFinder
- —Fish Stocking History — FloydFish Stocking History · MN DNR LakeFinder
- —Public Water Access Sites — FloydPublic Water Access Sites · MN DNR LakeFinder
Water Quality Trend: ↓ Declining
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.009 m/yr | 6 |
| Phosphorus | ↓ Declining | +0.87 µg/L/yr | 6 |
| Chlorophyll-a | → Stable | -0.07 µg/L/yr | 6 |
Ice Season
Historical ice data from Minnesota DNR (33 observations).
Estimated open water season: 214 days
| Earliest | Latest | |
|---|---|---|
| Ice-Out | 2012-03-24 (2012) | 2013-05-12 (2013) |
| Ice-In | 2019-11-07 (2019) | 2009-12-05 (2009) |
Most recent ice-out: 2025-04-07
EPA Impairment Status
Mud 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 MN03-0387-01 · Official waterbody report
County Ranking
Ranked #2 of 84 lakes in Becker County
Nearby Lakes in Becker County
Frequently asked questions about Mud Lake
What is the water quality grade for Mud Lake?
- Mud Lake in Becker County, Minnesota has a water quality grade of A (Excellent). Water clarity: 12.5 ft visibility. Phosphorus: 22 µg/L. Chlorophyll-a (algae): 5.9 µg/L. Maximum depth: 34 ft. Surface area: 1177.84 acres.
Is Mud Lake safe to swim in?
- Excellent for swimming, crystal clear water with minimal algae. Mud Lake has a water quality grade of A (Excellent). Algae concentration (chlorophyll-a) is 5.9 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Mud Lake?
- Mud Lake typically sits around 66°F at the surface in August, from 839 EPA Water Quality Portal field readings (2010–2025). That is a typical value for the month, not a live reading.
How deep is Mud Lake?
- Mud Lake has a maximum depth of 34 feet. The lake covers 1177.84 acres.
What fish are in Mud Lake?
- Fish species found in Mud Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, rock bass, sunfish, walleye, white sucker, yellow bullhead, yellow perch. Mud Lake is located in Becker County, Minnesota.
When does Mud Lake thaw?
- Mud Lake typically has ice-out around Apr 24. Ice typically forms around Nov 24. The open water season is approximately 214 days.
What is the water level at Mud Lake?
- The USGS snapshot on this page for Mud Lake is 972.78 ft of water-surface elevation, recorded Jul 6, 2026, 4:30 AM at gauge 05049900. Current Conditions hydrates a live NWIS reading from that same station when the gauge responds. A missed live fetch is not an all-clear.
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 low (14,060 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
210 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
MNPCA210 samples · 2020–2025
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H ~ Chlorophyll a-b-c Determination
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