Otter Lake
Otter Lake in Vilas County, Wisconsin has a water quality grade of C (Fair). Water clarity: 5 ft visibility. Phosphorus: 30.8 µg/L. Maximum depth: 30 ft. Surface area: 174 acres.
Wisconsin DNR lists Musky as common on Otter Lake. DNR survey details →
- Clarity
- 5 ft
- Max depth
- 30 ft
- Area
- 174 acres
- Type
- Eutrophic
- Trend
- → Stable
- Public access
- Yes
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Otter Lake is a 174-acre productive, nutrient-rich eutrophic lake in Vilas County, Wisconsin with a maximum depth of 30 feet. Water quality is graded C based on 1 sampling years through 2025. The lake supports 6 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available with 1 public boat landing. Compared to the 102 other monitored lakes in Vilas County, Otter Lake ranks #97 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-10-18. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyLimited data
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.
Generally safe for swimming, moderate water quality
Water Quality Grade: C (Fair)
Murky, only visible to about 5 ft. Phosphorus level: 30.8 µg/L. Trophic State Index: 54.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 5 ft | Not graded |
| Phosphorus | 30.8 µg/L | Fair |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 54 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Otter Lake
Compare lakeside cabins, hotels, and vacation rentals near Otter 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 Otter Lake
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Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Wisconsin DNR lists Musky as common on Otter Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Otter Lake C 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 1993. 2 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 30 ft |
| Surface Area | 174 acres |
| Public Access | Yes |
Recreation & Access
- Eagle LakePublic
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 Otter 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 | +0.095 m/yr | 7 |
EPA Impairment Status
Otter Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Source: EPA ATTAINS assessment unit WI10007690 · Official waterbody report
County Ranking
Ranked #97 of 103 lakes in Vilas County
Nearby Lakes With Higher Grades
Otter Lake holds Grade C. One nearby lake has a higher nutrient-and-algae grade — useful for a swim day, not a reason to skip lodging here.
Nearby Lakes in Vilas County
Frequently asked questions about Otter Lake
Where is Otter Lake?
- Otter Lake is a lake in Vilas County, Wisconsin. LakeQuality grades it C for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Otter Lake?
- Otter Lake in Vilas County, Wisconsin has a water quality grade of C (Fair). Water clarity: 5 ft visibility. Phosphorus: 30.8 µg/L. Maximum depth: 30 ft. Surface area: 174 acres.
Is Otter Lake safe to swim in?
- Generally safe for swimming, moderate water quality. Otter Lake has a water quality grade of C (Fair). Always check local health department advisories before swimming.
How deep is Otter Lake?
- Otter Lake has a maximum depth of 30 feet. The lake covers 174 acres.
What fish are in Otter Lake?
- Fish species found in Otter Lake include Musky, Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye. Otter Lake is located in Vilas County, Wisconsin.
What did the DNR fisheries survey find at Otter Lake?
- Wisconsin DNR lists Musky as common on Otter Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Otter Lake C 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.
Are there boat ramps on Otter Lake?
- Otter Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Eagle Lake. Public access is listed as yes.
Explore Otter Lake across LakeQuality
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Species activity outlook by water temperature and season
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High nutrients, frequent algae, reduced clarity
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Other Grade C Lakes in Wisconsin
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Where this data comes from
32 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX32 samples · 2020–2025
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
Impairment status from EPA ATTAINS 303(d) database
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