Alder Lake
Vilas County, Wisconsin264 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Alder Lake. Here is what has been measured.
- 2 aquatic invasives
- 30 ft max depth
- Public access
- Limited data
Alder Lake in Vilas County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 10.2 ft visibility. Maximum depth: 30 ft. Surface area: 264 acres.
Wisconsin DNR rates Walleye as abundant on Alder Lake. DNR survey details →
Alder Lake is a 264-acre lake in Vilas County, Wisconsin with a maximum depth of 30 feet. The lake supports 6 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-07-04. Methodology: how these readings are compared.
Alder Lake covers about 260 acres in Vilas County. For a place on the water, look through cabin and lake-house rentals near Alder Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.
What Alder Lake is good for
From access and monitoring records, not editorial picks.
- Clear water10.2 ft of visibility
- Fishing6 species recorded
- Deep water30 ft surveyed max depth
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
Whether Alder 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 Alder Lake
These are the measurements Wisconsin DNR publishes for Alder Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 10.2 ft. TSI 44.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 10.2ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| 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. | 44 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Alder Lake
Answers come straight from the public measurements and survey records on this page.
Blue-Green Algae (Cyanobacteria)
There’s no recent EPA CyAN cyanobacteria estimate for Alder Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was low (6,486 cells/mL) on April 18, 2026.
Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗
Wisconsin DNR rates Walleye as abundant on Alder Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Alder Lake’s water-quality measurements separately, and the water-quality trend over 6 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. 4 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
Max depth
30 ft
Surface area
264 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
91 sq mi
HydroLAKES / HydroSHEDS
Shoreline
3.3 mi
HydroLAKES / HydroSHEDS
Elevation
1,594 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Stays via Stay22
Stays near Alder Lake
Compare lakeside cabins, hotels, and vacation rentals near Alder 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 Alder Lake
Prices for Oct 16–18, 4 adults. Change dates on the map below.
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Follow Alder Lake’s readings
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Fish Species
Click a species to see every lake where it is documented.
Fishing Alder 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 6 years of monitoring (2020–2026).
Water clarity
Stable6 years
Nearby Lakes in Vilas County
Frequently asked questions about Alder Lake
Where is Alder Lake?
- Alder 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 Alder Lake?
- Alder Lake in Vilas County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 10.2 ft visibility. Maximum depth: 30 ft. Surface area: 264 acres.
Is Alder Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Alder Lake?
- Alder Lake has a maximum depth of 30 feet. The lake covers 264 acres.
What fish are in Alder Lake?
- Fish species found in Alder Lake include Musky, Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye. Alder Lake is located in Vilas County, Wisconsin.
What did the DNR fisheries survey find at Alder Lake?
- Wisconsin DNR rates Walleye as abundant on Alder Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Alder Lake’s water-quality measurements separately, and the water-quality trend over 6 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
Does Alder Lake have blue-green algae?
- There is no recent EPA CyAN cyanobacteria estimate for Alder Lake (clouds, ice, or an off-season gap). The most recent reading was low (6,486 cells/mL). Blue-green algae can appear and clear within days, so check Wisconsin's current advisory before swimming.
Can I fish at Alder Lake?
- Public access to Alder Lake is listed as yes on the lake record. 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 Alder Lake across LakeQuality
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Where this data comes from
45 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_WQX45 samples · 2020–2026
Monitoring station identifiers (1)
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)
Fish and recreation data from Wisconsin DNR Lakes