Loon Lake
Loon Lake in Vilas County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 14.5 ft visibility. Phosphorus: 12 µg/L. Maximum depth: 21 ft. Surface area: 36 acres.
Wisconsin DNR lists Panfish as present on Loon Lake. DNR survey details →
- Clarity
- 14.5 ft
- Max depth
- 21 ft
- Area
- 36 acres
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Why Loon Lake has no grade
We grade a lake only when the monitoring record supports a letter: at least three phosphorus or chlorophyll-a samples in the last ten years, scored against EPA National Lakes Assessment thresholds for this lake’s ecoregion. For Loon Lake, no nutrient or algae measurement meets the evidence bar (at least 3 samples within 10 years). Sampling here has recorded water clarity and phosphorus, but not algae (chlorophyll-a).
Not Rated is not an F. It is EPA Integrated Reporting Category 3 — insufficient information. The water here may be excellent or poor; nobody has measured enough of it to say. Everything below that has been measured is still reported on this page.
Sampling is run by WI DNR and volunteer programs, and published through the EPA Water Quality Portal. Read the full grading methodology.
Loon Lake is a 36-acre lake in Vilas County, Wisconsin with a maximum depth of 21 feet. The lake supports 3 documented fish species including Panfish, Largemouth Bass, and Smallmouth Bass.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-07-16. Grade methodology: LakeQuality methodology.
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Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Loon Lake
These readings exist but are not enough for an A–F grade — see why.
Good clarity, visible to about 14.5 ft. Phosphorus level: 12 µg/L. Trophic State Index: 39.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 14.5 ft | Not graded |
| Phosphorus | 12 µg/L | Not graded |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 39 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Loon Lake
Compare lakeside cabins, hotels, and vacation rentals near Loon 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 Loon Lake
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Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Wisconsin DNR lists Panfish as present on Loon Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality does not assign an A–F grade on Loon Lake — official chemistry is on file, not a letter. 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. 1 station on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 21 ft |
| Surface Area | 36 acres |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Loon 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.
Graded lakes near Loon Lake
Loon Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Vilas County
Frequently asked questions about Loon Lake
Where is Loon Lake?
- Loon Lake is a lake in Vilas County, Wisconsin. LakeQuality has not rated this lake (UNRATED) — there is not enough recent sampling to assign a letter.
What is the water quality grade for Loon Lake?
- Loon Lake in Vilas County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 14.5 ft visibility. Phosphorus: 12 µg/L. Maximum depth: 21 ft. Surface area: 36 acres.
Is Loon Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Loon Lake is not rated for water quality — its monitoring record does not meet the evidence bar. Always check local health department advisories before swimming.
How deep is Loon Lake?
- Loon Lake has a maximum depth of 21 feet. The lake covers 36 acres.
What fish are in Loon Lake?
- Fish species found in Loon Lake include Panfish, Largemouth Bass, Smallmouth Bass. Loon Lake is located in Vilas County, Wisconsin.
What did the DNR fisheries survey find at Loon Lake?
- Wisconsin DNR lists Panfish as present on Loon Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality does not assign an A–F grade on Loon Lake — official chemistry is on file, not a letter. Catch rate is not a swim clearance and is not a weekly bite report.
Explore Loon Lake across LakeQuality
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Where this data comes from
2 measurements from 1 monitoring station, 2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX2 samples · 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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Fish and recreation data from Wisconsin DNR Lakes