Half Moon Lake
Half Moon Lake in Bayfield County, Wisconsin has a water quality grade of B (Good). Water clarity: 8 ft visibility. Phosphorus: 17.2 µg/L. Maximum depth: 10 ft. Surface area: 106 acres.
- Clarity
- 8 ft
- Max depth
- 10 ft
- Area
- 106 acres
- Type
- Mesotrophic
- Trend
- ↑ Improving
- Public access
- Yes
Next lake in Bayfield County
Half Moon Lake is a 106-acre mesotrophic lake in Bayfield County, Wisconsin with a maximum depth of 10 feet. Water quality is graded B based on 1 sampling years through 2025. Overall water quality is improving over recent sampling years. The lake supports 3 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 2 public boat landings. Compared to the 23 other monitored lakes in Bayfield County, Half Moon Lake ranks #10 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-08-26. Grade methodology: LakeGrade 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)
Moderate clarity, visible to about 8 ft. Phosphorus level: 17.2 µg/L. Trophic State Index: 46.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 8 ft | Not graded |
| Phosphorus | 17.2 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 46 | Mesotrophic |
Moderate nutrients, good water quality
Where to stay near Half Moon Lake
Compare lakeside cabins, hotels, and vacation rentals near Half Moon Lake in Bayfield 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 Half Moon Lake
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Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 10 ft |
| Surface Area | 106 acres |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Half Moon LakePublic
- Fire LakePublic
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Half Moon Lake
WI DNR Lake Profile
Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 2014. 2 stations on file (most recent sample 2025).
Fish Species (DNR-rated)
Water Quality Trend: ↑ Improving
Based on 6 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↑ Improving | +0.225 m/yr | 4 |
| Phosphorus | ↑ Improving | -0.38 µg/L/yr | 6 |
Regulated Pollution Sources Nearby
1 EPA-permitted facility operate within about 5 miles of Half Moon Lake under Clean Water Act (NPDES) discharge permits. 1 facility has a reported Clean Water Act violation in the past three years.
- Iron River Sanitary District 1Iron River · 0.5 mi away · NPDES WI0022446Recent violation
Facilities permitted to discharge under the Clean Water Act within ~5 miles; proximity does not by itself mean a facility affects this lake. Source: EPA ECHO (ICIS-NPDES), as of 2026-07.
County Ranking
Ranked #10 of 24 lakes in Bayfield County
Nearby Lakes in Bayfield County
Frequently asked questions about Half Moon Lake
What is the water quality grade for Half Moon Lake?
- Half Moon Lake in Bayfield County, Wisconsin has a water quality grade of B (Good). Water clarity: 8 ft visibility. Phosphorus: 17.2 µg/L. Maximum depth: 10 ft. Surface area: 106 acres.
Is Half Moon Lake safe to swim in?
- Good for swimming, clear water with low algae levels. Half Moon Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.
How deep is Half Moon Lake?
- Half Moon Lake has a maximum depth of 10 feet. The lake covers 106 acres.
What fish are in Half Moon Lake?
- Fish species found in Half Moon Lake include Panfish, Largemouth Bass, Northern Pike. Half Moon Lake is located in Bayfield County, Wisconsin.
Are there boat ramps on Half Moon Lake?
- Half Moon Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Half Moon Lake, Fire Lake. Public access is listed as yes.
Explore Half Moon Lake across LakeGrade
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Moderate nutrients, good water quality
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State Parks Near Half Moon Lake
Other Grade B Lakes in Wisconsin
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Where this data comes from
31 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_WQX31 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
Regulated discharger data from EPA ECHO (ICIS-NPDES)
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