Forest Lake
Forest Lake in Vilas County, Wisconsin has a water quality grade of B (Good). Water clarity: 22.2 ft visibility. Phosphorus: 12.8 µg/L. Maximum depth: 60 ft. Surface area: 468 acres.
Wisconsin DNR lists Panfish as common on Forest Lake. DNR survey details →
- Clarity
- 22.2 ft
- Max depth
- 60 ft
- Area
- 468 acres
- Type
- Oligotrophic
- Trend
- → Stable
- Public access
- Yes
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Forest Lake is a 468-acre cold, clear oligotrophic lake in Vilas County, Wisconsin with a maximum depth of 60 feet. Water quality is graded B based on 1 sampling years through 2026. The lake supports 5 documented fish species including Panfish, Largemouth Bass, and Smallmouth Bass. Public access is available with 1 public boat landing. Compared to the 102 other monitored lakes in Vilas County, Forest Lake ranks #37 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-15. 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)
Crystal clear, you can see 22.2 ft down. Phosphorus level: 12.8 µg/L. Trophic State Index: 37.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 22.2 ft | Not graded |
| Phosphorus | 12.8 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 37 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Forest Lake
Compare lakeside cabins, hotels, and vacation rentals near Forest 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 Forest 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 Forest Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was moderate (84,723 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 ↗
Wisconsin DNR lists Panfish as common on Forest Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Forest Lake B from EPA Water Quality Portal chemistry, and the water-quality trend over 7 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1990. 10 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 60 ft |
| Surface Area | 468 acres |
| Public Access | Yes |
Recreation & Access
- Lac du LunePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Forest Lake
Invasive & Introduced Species
Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.
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 | 6 |
| Phosphorus | → Stable | -0.06 µg/L/yr | 7 |
County Ranking
Ranked #37 of 103 lakes in Vilas County
Nearby Lakes in Vilas County
Frequently asked questions about Forest Lake
Where is Forest Lake?
- Forest 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 Forest Lake?
- Forest Lake in Vilas County, Wisconsin has a water quality grade of B (Good). Water clarity: 22.2 ft visibility. Phosphorus: 12.8 µg/L. Maximum depth: 60 ft. Surface area: 468 acres.
Is Forest Lake safe to swim in?
- Good for swimming, clear water with low algae levels. Forest Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.
How deep is Forest Lake?
- Forest Lake has a maximum depth of 60 feet. The lake covers 468 acres.
What fish are in Forest Lake?
- Fish species found in Forest Lake include Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye. Forest Lake is located in Vilas County, Wisconsin.
What did the DNR fisheries survey find at Forest Lake?
- Wisconsin DNR lists Panfish as common on Forest Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Forest Lake B from EPA Water Quality Portal chemistry, and the water-quality trend over 7 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
Does Forest Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Forest Lake (clouds, ice, or an off-season gap). The most recent reading was moderate (84,723 cells/mL). Blue-green algae can appear and clear within days, so check Wisconsin's current advisory before swimming.
Are there boat ramps on Forest Lake?
- Forest Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Lac du Lune. Public access is listed as yes.
Explore Forest Lake across LakeQuality
Depth, room, public access, and the state wake-sport rules
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Fish species and best lakes in Vilas County
Species activity outlook by water temperature and season
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Where to stay at Wisconsin's top lakes, each with its grade
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Low nutrients, clear water, excellent for swimming
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Where this data comes from
46 measurements from 1 monitoring station, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX46 samples · 2020–2026
Analytical methods
- Phosphorus by Colorimetry
Monitoring station identifiers (1)
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)
Fish and recreation data from Wisconsin DNR Lakes
Named boat-access points from the USGS National Boat Ramps inventory