Mud Lake
Becker County, MinnesotaMesotrophic
Mud Lake comes in at a B on the grading rubric — a respectable showing for a Minnesota lake of its size and depth. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.
The lake sits in the mesotrophic zone — the band where most well-managed Minnesota lakes fall. Mud Lake reaches 34 ft at its deepest point — typical for Minnesota mid-sized lakes, with seasonal stratification but limited cold-water refuge. At 1,178 acres, Mud Lake is one of the larger lakes in Becker County, with 9.7 miles of shoreline supporting multiple distinct use patterns. Among the 93 graded lakes in Becker County, Mud Lake sits at rank 37, above the county median.
Zebra mussel presence at Mud Lake means the lake's clarity numbers carry an asterisk — filtered water is not the same as nutrient-poor water. The fishery includes walleye alongside the lake's other 16 documented species — a notable draw for Minnesota anglers. Public access is available — the lake is on the Minnesota PCA public-access list. Ice-out has been recorded 24 times at Mud Lake, with a median around Apr 24. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-09-29. Grade methodology: LakeGrade methodology.
Swimming Safety
Good for swimming, clear water with low algae levels
Water Quality Grade: B, Good
Good clarity, visible to about 11.5 ft. Phosphorus level: 23.5 µg/L. Trophic State Index: 46.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 11.5 ft | B |
| Phosphorus | 23.5 µg/L | B |
| Chlorophyll-a (Algae) | No data | |
| Trophic State Index (TSI) | 46 | Mesotrophic |
Moderate nutrients, good water quality
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 34 ft |
| Surface Area | 1.2K acres |
| Shoreline Length | 9.7 mi |
| Littoral Zone | 73% |
| Public Access | Yes |
Fish Species
Click a species to see all Minnesota and Wisconsin lakes where it is found.
→ Best fishing times for Mud Lake (14-day solunar calendar)
→ Is it safe to eat fish from Mud Lake? (mercury & PFAS guide)
→ Mud Lake fishing regulations (limits, seasons, special rules)
Invasive Species
Water Quality Trend: ↓ Declining
Based on 5 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.135 m/yr | 5 |
| Phosphorus | ↓ Declining | +1.25 µg/L/yr | 5 |
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
Location
County Ranking
Ranked #37 of 93 lakes in Becker County
Nearby Lakes in Becker County
More Minnesota Lake Rankings
State Parks Near Mud Lake
Other Grade B Lakes in Minnesota
Mesotrophic Lakes in Minnesota
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.
- —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
Data Sources
Water quality data from the EPA Water Quality Portal
Grading methodology based on Metropolitan Council standards
Lake details from Minnesota DNR LakeFinder
Ice data from Minnesota DNR Climate
Most recent sample: 2024-09-29
Monitoring stations: 1