Shannon Lake
Shannon Lake in Vilas County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 6.9 ft visibility. Phosphorus: 16.5 µg/L. Maximum depth: 30 ft. Surface area: 35 acres.
Wisconsin DNR lists Panfish as common on Shannon Lake. DNR survey details →
- Clarity
- 6.9 ft
- Max depth
- 30 ft
- Area
- 35 acres
- Trend
- → Stable
- Public access
- Yes
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Why Shannon 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 Shannon 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.
Shannon Lake is a 35-acre lake in Vilas County, Wisconsin with a maximum depth of 30 feet. The lake supports 3 documented fish species including Panfish, Largemouth Bass, and Trout. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2022-08-24. Grade methodology: LakeQuality methodology.
Watch Shannon Lake water quality
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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 Shannon Lake
These readings exist but are not enough for an A–F grade — see why.
Moderate clarity, visible to about 6.9 ft. Phosphorus level: 16.5 µg/L. Trophic State Index: 47.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 6.9 ft | Not graded |
| Phosphorus | 16.5 µg/L | Not graded |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 47 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Shannon Lake
Compare lakeside cabins, hotels, and vacation rentals near Shannon 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 Shannon Lake
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Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Wisconsin DNR lists Panfish as common on Shannon 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 Shannon Lake — official chemistry is on file, not a letter, 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. 1 station on file (most recent sample 2022).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 30 ft |
| Surface Area | 35 acres |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Shannon 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 Shannon Lake
Water Quality Trend: → Stable
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | -0.036 m/yr | 6 |
| Phosphorus | → Stable | -0.01 µg/L/yr | 5 |
EPA Impairment Status
Shannon 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 WI10026107 · Official waterbody report
Graded lakes near Shannon Lake
Shannon Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Vilas County
Frequently asked questions about Shannon Lake
Where is Shannon Lake?
- Shannon 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 Shannon Lake?
- Shannon Lake in Vilas County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 6.9 ft visibility. Phosphorus: 16.5 µg/L. Maximum depth: 30 ft. Surface area: 35 acres.
Is Shannon Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Shannon 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 Shannon Lake?
- Shannon Lake has a maximum depth of 30 feet. The lake covers 35 acres.
What fish are in Shannon Lake?
- Fish species found in Shannon Lake include Panfish, Largemouth Bass, Trout. Shannon Lake is located in Vilas County, Wisconsin.
What did the DNR fisheries survey find at Shannon Lake?
- Wisconsin DNR lists Panfish as common on Shannon 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 Shannon Lake — official chemistry is on file, not a letter, 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.
Are there boat ramps on Shannon Lake?
- Shannon Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Shannon Lake. Public access is listed as yes.
Explore Shannon Lake across LakeQuality
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Where this data comes from
3 measurements from 1 monitoring station, 2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX3 samples · 2022
Analytical methods
- Phosphorus by Colorimetry
- Turbidity in Water
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