Mcdonald Lake
Vilas County, WisconsinView mapDirections
Wisconsin DNR publishes the water-quality measurements for Mcdonald Lake. Here is what has been measured.
- Mesotrophic
- 17 ft max depth
- Public access
Mcdonald Lake in Vilas County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 8.6 ft visibility. Phosphorus: 20.2 µg/L.
Mcdonald Lake is a mesotrophic lake in Vilas County, Wisconsin with an estimated average depth of about 17 feet. Overall water quality is improving over recent sampling years. Limited fish-species data available. Public access is available with 1 public boat landing. Compared to the 102 other monitored lakes in Vilas County, Mcdonald Lake ranks #29 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-22. Methodology: how these readings are compared.
What Mcdonald Lake is good for
From access and monitoring records, not editorial picks.
- Boat launch1 documented ramp
Swimming conditions
Readings onlyLow algae
Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Mcdonald Lake is safe to swim in today is a call for the Wisconsin Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Mcdonald Lake
These are the measurements Wisconsin DNR publishes for Mcdonald Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Moderate clarity, visible to about 8.6 ft. Phosphorus 20.2 µg/L. TSI 47.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 8.6ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 20.2µg/L | Good GoodFairPoor |
| 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. | 47 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Mcdonald Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Mcdonald Lake typically sits around 76°F at the surface in August. Summer average is about 73°F. Usually warmest in Aug (about 76°F) and coldest in Jun (about 70°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (70°F) to its warmest (76°F).
Typical surface water temperature by month, from 10 field readings (2024–2025) via the EPA Water Quality Portal. See the full Mcdonald Lake water temperature breakdown →
Lake Details
Max depth
~17 ft est.
Public access
Yes
Listed by Wisconsin DNR
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Wisconsin has not published bathymetry for Mcdonald Lake.
Lake Size & Watershed
Watershed (drainage) area
575 sq mi
HydroLAKES / HydroSHEDS
Surface area
42 acres
HydroLAKES / HydroSHEDS
Shoreline
1.4 mi
HydroLAKES / HydroSHEDS
Elevation
1,624 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS). Mean depth here is modelled, not surveyed — HydroLAKES v1.0 estimates lake depth from surrounding terrain rather than from soundings. Treat it as an approximation, and prefer a state bathymetric survey where one exists.
Recreation & Access
- Wisconsin River - Hwy 70Public
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Mcdonald Lake
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Top-rated places to stay near Mcdonald Lake
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Follow Mcdonald Lake’s readings
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Fishing Mcdonald Lake
Water Quality Trend: Improving
Based on 7 years of monitoring (2020–2026).
Water clarity
Improving6 years
Phosphorus
Improving-1.88 µg/L/yr7 years
Nearby Lakes in Vilas County
Frequently asked questions about Mcdonald Lake
Where is Mcdonald Lake?
- Mcdonald Lake is a lake in Vilas County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Mcdonald Lake?
- Mcdonald Lake in Vilas County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 8.6 ft visibility. Phosphorus: 20.2 µg/L.
Is Mcdonald Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Mcdonald Lake?
- Mcdonald Lake typically sits around 76°F at the surface in August, from 10 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Mcdonald Lake?
- No published bathymetric survey covers Mcdonald Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 17 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Are there boat ramps on Mcdonald Lake?
- Mcdonald Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Wisconsin River - Hwy 70. Public access is listed as yes.
Can I fish at Mcdonald Lake?
- Mcdonald 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 Wisconsin's fish and wildlife agency, so check its current regulations before you go.
Explore Mcdonald Lake across LakeQuality
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Where this data comes from
49 measurements from 2 monitoring stations, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX49 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
Monitoring station identifiers (2)
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory