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LakeQuality

Mud Lake

NR
Not yet rated
Eutrophic · 126 acres
Limited DataEutrophic

Mud Lake in Washburn County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Phosphorus: 70.7 µg/L. Maximum depth: 13 ft. Surface area: 126 acres.

Wisconsin DNR lists Panfish as common on Mud Lake. DNR survey details →

Max depth
13 ft
Area
126 acres
Trend
Declining
Public access
Yes

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Why Mud Lake has no grade

We grade a lake only when the monitoring record supports a letter: 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, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded phosphorus, but not water clarity 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 WI DNR and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.

Mud Lake is a 126-acre lake in Washburn County, Wisconsin with a maximum depth of 13 feet. Overall water quality is declining over recent sampling years. The lake supports 4 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 2 public boat landings.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2022-09-07. Grade methodology: LakeQuality methodology.

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Swimming Safety

Not rated

Limited data

Not rated for swimming — there is not enough monitoring data to judge this lake

Compare the safest swimming lakes near Hayward

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Water quality measurements for Mud Lake

These readings exist but are not enough for an A–F grade — see why.

No clarity data. Phosphorus level: 70.7 µg/L. Trophic State Index: 66.

MetricValueGrade
Water Clarity (Secchi Depth)No recent samples
Phosphorus70.7 µg/LNot graded
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)66Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Mud Lake

Compare lakeside cabins, hotels, and vacation rentals near Mud Lake in Washburn County, Wisconsin — 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

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Planning a whole trip? See where to stay at Wisconsin’s top lakes →

DNR fisheries survey

Wisconsin DNR lists Panfish as common on Mud Lake.

A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality does not assign an A–F grade on Mud Lake — official chemistry is on file, not a letter, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.

WI DNR Lake Profile

Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1994. 2 stations on file (most recent sample 2025).

Fish Species (DNR-rated)

Panfish(Common)Largemouth Bass(Common)Northern Pike(Common)Walleye(Present)

Lake Details

CharacteristicValue
Maximum Depth13 ft
Surface Area126 acres
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
2 sq mi
Shoreline
2.6 mi
Elevation
1,217 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Recreation & Access

2
Boat Landings
Yes
Public Access
  • Red LakePublic

Showing 1 of 2 documented landings from the USGS National Boat Ramps inventory.

Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps

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.

Curly-Leaf Pondweed

Based on 6 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-0.125 m/yr6
See year-by-year chart →

EPA Impairment Status

Mud Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5R).

Causes of impairment

Nutrients (phosphorus, nitrogen)

Source: EPA ATTAINS assessment unit WI10004589 · Official waterbody report · Matched by proximity (2.18 km)

Graded lakes near Mud Lake

Mud Lake has no grade, but these lakes within a short drive do.

Nearby Lakes in Washburn County

Frequently asked questions about Mud Lake

Where is Mud Lake?

Mud Lake is a lake in Washburn County, Wisconsin. LakeQuality has not rated this lake (UNRATED) — there is not enough recent sampling to assign a letter.

What is the water quality grade for Mud Lake?

Mud Lake in Washburn County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Phosphorus: 70.7 µg/L. Maximum depth: 13 ft. Surface area: 126 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 13 feet. The lake covers 126 acres.

What fish are in Mud Lake?

Fish species found in Mud Lake include Panfish, Largemouth Bass, Northern Pike, Walleye. Mud Lake is located in Washburn County, Wisconsin.

What did the DNR fisheries survey find at Mud Lake?

Wisconsin DNR lists Panfish as common on Mud Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality does not assign an A–F grade on Mud Lake — official chemistry is on file, not a letter, and the water-quality trend over 6 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.

Are there boat ramps on Mud Lake?

Mud Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Red Lake, among others. Public access is listed as yes.

Where this data comes from

2 measurements from 1 monitoring station, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Wisconsin Department of Natural ResourcesWIDNR_WQX2 samples · 2022

Analytical methods

  • Phosphorus by Colorimetry
  • Turbidity in Water
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)

Fish and recreation data from Wisconsin DNR Lakes

Named boat-access points from the USGS National Boat Ramps inventory