Big Lake
Big Lake in Vilas County, Wisconsin has a water quality grade of B (Good). Water clarity: 12.5 ft visibility. Phosphorus: 12.9 µg/L.
- Clarity
- 12.5 ft
- Max depth
- ~76 ft est.
- Type
- Mesotrophic
- Trend
- → Stable
- Public access
- Yes
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Big Lake is a mesotrophic lake in Vilas County, Wisconsin with an estimated average depth of about 76 feet. Water quality is graded B based on 1 sampling years through 2026. Limited fish-species data available. Public access is available with 3 public boat landings. Compared to the 102 other monitored lakes in Vilas County, Big Lake ranks #22 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-27. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyLow algae
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.
Good for swimming, clear water with low algae levels
Water Quality Grade: B (Good)
Good clarity, visible to about 12.5 ft. Phosphorus level: 12.9 µg/L. Trophic State Index: 41.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 12.5 ft | Not graded |
| Phosphorus | 12.9 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 41 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Big Lake
Compare lakeside cabins, hotels, and vacation rentals near Big 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 Big Lake
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Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Big Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (164,437 cells/mL) on May 23, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | ~76 ft est. |
| Average Depth | ~19 ft est. |
| Public Access | Yes |
Depth marked “est.” is a modeled maximum from GLOBathy (Khazaei et al. 2022, CC0), not a measured survey. Wisconsin has not published bathymetry for Big Lake.
Lake Size & Watershed
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
- Big Lake CampgroundPublic
- Big Lake - Hwy KPublic
- Rice CreekPublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fishing Big Lake
Water Quality Trend: → Stable
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | +0.25 m/yr | 7 |
| Phosphorus | → Stable | +0.01 µg/L/yr | 6 |
County Ranking
Ranked #22 of 103 lakes in Vilas County
Nearby Lakes in Vilas County
Frequently asked questions about Big Lake
Where is Big Lake?
- Big Lake is a lake in Vilas County, Wisconsin. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Big Lake?
- Big Lake in Vilas County, Wisconsin has a water quality grade of B (Good). Water clarity: 12.5 ft visibility. Phosphorus: 12.9 µg/L.
Is Big Lake safe to swim in?
- Good for swimming, clear water with low algae levels. Big Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.
How deep is Big Lake?
- No published bathymetric survey covers Big Lake, so its depth has not been measured. The HydroLAKES global model estimates an average depth of about 76 feet, but that is a modelled estimate derived from surrounding terrain rather than a measurement on the water, so treat it as approximate.
Does Big Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Big Lake (clouds, ice, or an off-season gap). The most recent reading was high (164,437 cells/mL). Blue-green algae can appear and clear within days, so check Wisconsin's current advisory before swimming.
Are there boat ramps on Big Lake?
- Big Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Big Lake Campground, Big Lake - Hwy K, Rice Creek. Public access is listed as yes.
Explore Big Lake across LakeQuality
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Fish species and best lakes in Vilas County
Species activity outlook by water temperature and season
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Moderate nutrients, good water quality
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More Wisconsin Lake Rankings
Other Grade B Lakes in Wisconsin
Mesotrophic Lakes in Wisconsin
Where this data comes from
40 measurements from 3 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_WQX40 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
Monitoring station identifiers (3)
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Named boat-access points from the USGS National Boat Ramps inventory