Mayo Lake
Mayo Lake in Crow Wing County, Minnesota has a water quality grade of C (Fair). Water clarity: 4.8 ft visibility. Phosphorus: 28 µg/L. Chlorophyll-a (algae): 8.5 µg/L. Maximum depth: 22 ft. Surface area: 164.3 acres.
- Clarity
- 4.8 ft
- Typical in August
- 72°F
- Max depth
- 22 ft
- Area
- 164 acres
- Type
- Eutrophic
- Trend
- ↑ Improving
- Public access
- No
Next lake in Crow Wing County
Mayo Lake is a 164-acre productive, nutrient-rich eutrophic lake in Crow Wing County, Minnesota with a maximum depth of 22 feet. Water quality is graded C based on 2 sampling years through 2024. Overall water quality is improving over recent sampling years. The lake supports 12 documented fish species including black bullhead, black crappie, and bluegill. No public access — the lake is private or restricted. Compared to the 84 other monitored lakes in Crow Wing County, Mayo Lake ranks #78 for water quality.
Source: EPA Water Quality Portal sampling records, Minnesota DNR LakeFinder, last sampled 2024-10-03. Grade methodology: LakeGrade methodology.
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Swimming Safety
Grade onlyModerate
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.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Murky, only visible to about 4.8 ft. Phosphorus level: 28 µg/L. Chlorophyll-a: 8.5 µg/L. Trophic State Index: 53.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 4.8 ft | Not graded |
| Phosphorus | 28 µg/L | Fair |
| Chlorophyll-a (Algae) | 8.5 µg/L | Fair |
| Trophic State Index (TSI) | 53 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Mayo Lake
Compare lakeside cabins, hotels, and vacation rentals near Mayo Lake in Crow Wing 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.
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Water Temperature
Mayo Lake typically sits around 72°F at the surface in August. Summer average is about 72°F. Usually warmest in Jun (about 72°F) and coldest in Sep (about 64°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 16 field readings (2016–2024) via the EPA Water Quality Portal. See the full Mayo Lake water temperature breakdown →
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 22 ft |
| Surface Area | 164 acres |
| Shoreline Length | 3.5 mi |
| Littoral Zone | 89% |
| Public Access | No |
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 Mayo Lake
DNR Fisheries Survey Summary
7 surveys on file from MN DNR Fisheries. Most recent: 2019-08-05 (Standard Survey).
Top Species by Catch Rate
| Species | Avg CPUE | Avg Weight |
|---|---|---|
| Bluegill | 25.00 | 0.16 lb |
| Black Bullhead | 12.78 | 0.54 lb |
| Green Sunfish | 11.49 | 0.04 lb |
| CNM | 9.01 | — |
| Yellow Bass | 7.93 | 0.76 lb |
| GOS | 7.75 | — |
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
Black Bullhead
Green Sunfish
Yellow Bass
From the 2019-08-05 survey
Mayo Lake is a 165 acre lake located two miles southwest of Pequot Lakes in Crow Wing County. The maximum depth is 22', with 95% of the lake 15' or less. Emergent vegetation such as bulrush and water lilies surround much of the lake. Protection of aquatic vegetation, especially emergent vegetation, is important for…
DNR Reports & Resources
Minnesota DNR LakeFinder publishes lake survey, fish stocking, water access, and aquatic plant data for Mayo Lake. 2 reports on file.
These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).
- —Fisheries Lake Survey — MayoFisheries Lake Survey · MN DNR LakeFinder
- —Aquatic Plant Report — Mayo (1540)Aquatic Plant Report · MN DNR LakeFinder
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.029 m/yr | 6 |
| Phosphorus | ↑ Improving | -0.89 µg/L/yr | 6 |
| Chlorophyll-a | ↑ Improving | -0.16 µg/L/yr | 6 |
EPA Impairment Status
Mayo 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 MN18-0408-00 · Official waterbody report
County Ranking
Ranked #78 of 85 lakes in Crow Wing County
Nearby Lakes With Higher Grades
Mayo Lake holds Grade C. 2 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Crow Wing County
Frequently asked questions about Mayo Lake
What is the water quality grade for Mayo Lake?
- Mayo Lake in Crow Wing County, Minnesota has a water quality grade of C (Fair). Water clarity: 4.8 ft visibility. Phosphorus: 28 µg/L. Chlorophyll-a (algae): 8.5 µg/L. Maximum depth: 22 ft. Surface area: 164.3 acres.
Is Mayo Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Mayo Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 8.5 µg/L. Always check local health department advisories before swimming.
What is the water temperature of Mayo Lake?
- Mayo Lake typically sits around 72°F at the surface in August, from 16 EPA Water Quality Portal field readings (2016–2024). That is a typical value for the month, not a live reading.
How deep is Mayo Lake?
- Mayo Lake has a maximum depth of 22 feet. The lake covers 164.3 acres.
What fish are in Mayo Lake?
- Fish species found in Mayo Lake include black bullhead, black crappie, bluegill, bowfin (dogfish), brown bullhead, green sunfish, hybrid sunfish, largemouth bass, northern pike, pumpkinseed, yellow bullhead, yellow perch. Mayo Lake is located in Crow Wing County, Minnesota.
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Where this data comes from
39 measurements from 2 monitoring stations, 2020–2024. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Minnesota Pollution Control Agency - Ambient Surface Water
MNPCA39 samples · 2020–2024
Analytical methods
- Field measurement/observation, generic method
- Phosphorus by Two Reagent Colorimetry
- 10200 H 2 ~ Chlorophyll a-b-c Determination by spectrophotometer
Monitoring station identifiers (2)
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