Gunlock Lake
Vilas County, WisconsinView mapDirections
Wisconsin DNR publishes the water-quality measurements for Gunlock Lake. Here is what has been measured.
- Mesotrophic
- 54 ft max depth
Gunlock Lake in Vilas County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 9 ft visibility. Phosphorus: 18.9 µg/L.
Gunlock Lake is a mesotrophic lake in Vilas County, Wisconsin with an estimated average depth of about 54 feet. Overall water quality is declining over recent sampling years. Compared to the 102 other monitored lakes in Vilas County, Gunlock Lake ranks #57 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-19. Methodology: how these readings are compared.
For a place on the water, look through cabin and lake-house rentals near Gunlock Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
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 Gunlock 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 Gunlock Lake
These are the measurements Wisconsin DNR publishes for Gunlock 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 9 ft. Phosphorus 18.9 µg/L. TSI 46.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 9ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | 18.9µg/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. | 46 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Gunlock Lake
Answers come straight from the public measurements and survey records on this page.
Water Temperature
Gunlock Lake typically sits around 72°F at the surface in August. Summer average is about 74°F. Usually warmest in Jul (about 75°F) and coldest in Apr (about 50°F). These are typical values by month — not a live reading.
Column height runs from this lake’s coldest month (50°F) to its warmest (75°F).
Typical surface water temperature by month, from 17 field readings (2024–2026) via the EPA Water Quality Portal. See the full Gunlock Lake water temperature breakdown →
Lake Details
Max depth
~54 ft est.
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Wisconsin has not published bathymetry for Gunlock Lake.
Lake Size & Watershed
Watershed (drainage) area
65 sq mi
HydroLAKES / HydroSHEDS
Surface area
247 acres
HydroLAKES / HydroSHEDS
Shoreline
4.6 mi
HydroLAKES / HydroSHEDS
Elevation
1,572 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.
Stays via Stay22
Stays near Gunlock Lake
Compare lakeside cabins, hotels, and vacation rentals near Gunlock Lake in Vilas 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 Gunlock Lake
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Fishing Gunlock Lake
Water Quality Trend: Worsening
Based on 7 years of monitoring (2020–2026).
Water clarity
Worsening7 years
Phosphorus
Stable-0.16 µg/L/yr7 years
Nearby Lakes in Vilas County
Frequently asked questions about Gunlock Lake
Where is Gunlock Lake?
- Gunlock 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 Gunlock Lake?
- Gunlock Lake in Vilas County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 9 ft visibility. Phosphorus: 18.9 µg/L.
Is Gunlock 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 Gunlock Lake?
- Gunlock Lake typically sits around 72°F at the surface in August, from 17 EPA Water Quality Portal field readings (2024–2026). That is a typical value for the month, not a live reading.
How deep is Gunlock Lake?
- No published bathymetric survey covers Gunlock Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 54 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
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Where this data comes from
76 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_WQX76 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)