Largon Lake
Largon Lake in Polk County, Wisconsin has a water quality grade of D (Nutrient-rich). Water clarity: 2.5 ft visibility. Phosphorus: 55.8 µg/L. Maximum depth: 10 ft. Surface area: 135 acres.
Wisconsin DNR lists Panfish as common on Largon Lake. DNR survey details →
- Clarity
- 2.5 ft
- Max depth
- 10 ft
- Area
- 135 acres
- Type
- Eutrophic
- Trend
- → Stable
- Public access
- Yes
Grade D measures nutrients and algae, not whether this is a good place for a cabin trip. Cabins and rentals near Largon Lake →
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Largon Lake is a 135-acre productive, nutrient-rich eutrophic lake in Polk County, Wisconsin with a maximum depth of 10 feet. Water quality is graded D based on 1 sampling years through 2022. The lake supports 3 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 1 public boat landing. Compared to the 54 other monitored lakes in Polk County, Largon Lake ranks #48 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2022-10-20. Grade methodology: LakeQuality methodology.
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Swimming Safety
Grade onlyElevated nutrients
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.
Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum
Water Quality Grade: D (Nutrient-rich)
Very murky, less than 2.5 ft of visibility. Phosphorus level: 55.8 µg/L. Trophic State Index: 63.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 2.5 ft | Not graded |
| Phosphorus | 55.8 µg/L | Poor |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 63 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Largon Lake
Compare lakeside cabins, hotels, and vacation rentals near Largon Lake in Polk 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. The water-quality grade measures nutrients and algae, not lodging — cabins and rentals around Largon Lake are listed below.
Top-rated places to stay near Largon 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 Largon Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Largon Lake D from EPA Water Quality Portal chemistry, and the water-quality trend over 2 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. 3 stations on file (most recent sample 2022).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 10 ft |
| Surface Area | 135 acres |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Largon 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 Largon 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 2 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | → Stable | 0 m/yr | 2 |
| Phosphorus | → Stable | -0.7 µg/L/yr | 2 |
EPA Impairment Status
Largon Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5R).
Causes of impairment
Source: EPA ATTAINS assessment unit WI10005220 · Official waterbody report
County Ranking
Ranked #48 of 55 lakes in Polk County
Nearby Lakes With Higher Grades
Largon Lake holds Grade D. 2 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.
See full comparison →Nearby Lakes in Polk County
Frequently asked questions about Largon Lake
Where is Largon Lake?
- Largon Lake is a lake in Polk County, Wisconsin. LakeQuality grades it D for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Largon Lake?
- Largon Lake in Polk County, Wisconsin has a water quality grade of D (Nutrient-rich). Water clarity: 2.5 ft visibility. Phosphorus: 55.8 µg/L. Maximum depth: 10 ft. Surface area: 135 acres.
Is Largon Lake safe to swim in?
- Nutrients and algae run higher than average — check local advisories before swimming, and skip the water if you see scum. Largon Lake has a water quality grade of D (Nutrient-rich). Always check local health department advisories before swimming.
How deep is Largon Lake?
- Largon Lake has a maximum depth of 10 feet. The lake covers 135 acres.
What fish are in Largon Lake?
- Fish species found in Largon Lake include Panfish, Largemouth Bass, Northern Pike. Largon Lake is located in Polk County, Wisconsin.
What did the DNR fisheries survey find at Largon Lake?
- Wisconsin DNR lists Panfish as common on Largon Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Largon Lake D from EPA Water Quality Portal chemistry, and the water-quality trend over 2 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Largon Lake?
- Largon Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Largon Lake. Public access is listed as yes.
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Where this data comes from
53 measurements from 1 monitoring station, 2021–2022. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX53 samples · 2021–2022
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