Long Lake
Oneida County, Wisconsin113 acresView mapDirections
Wisconsin DNR publishes the water-quality measurements for Long Lake. Here is what has been measured.
- Impaired · Mercury
- 58 ft max depth
- Public access
- Limited data
Long Lake in Oneida County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 10.5 ft visibility. Maximum depth: 58 ft. Surface area: 113 acres.
Wisconsin DNR lists Panfish as common on Long Lake. DNR survey details →
Long Lake is a 113-acre lake in Oneida County, Wisconsin with a maximum depth of 58 feet. Water clarity is improving over recent sampling years. The lake supports 4 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available with 1 public boat landing.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2023-08-06. Methodology: how these readings are compared.
What Long Lake is good for
From access and monitoring records, not editorial picks.
- Clear water10.5 ft of visibility
- Boat launch1 documented ramp
- Fishing4 species recorded
- Deep water58 ft surveyed max depth
Swimming conditions
No readingLimited data
Nutrient and algae readings are not a swimming clearance. Long Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
Whether Long Lake is safe to swim in today is a call for the Wisconsin Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.
Water quality measurements for Long Lake
These are the measurements Wisconsin DNR publishes for Long Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.
Good clarity, visible to about 10.5 ft. TSI 43.
| Measure | Reading | Where it sits |
|---|---|---|
| Water clarity (Secchi depth) | 10.5ft | Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer. |
| Total phosphorus | No reading The nutrient that most limits algae growth in freshwater. More phosphorus, more algae potential. | |
| Chlorophyll-a (algae) | No reading The green pigment in algae — a direct measure of how much algae is in the water. | |
| Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a. | 43 | Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic |
Moderate nutrients, good water quality
Ask about Long Lake
Answers come straight from the public measurements and survey records on this page.
Wisconsin DNR lists Panfish as common on Long Lake.
A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Long Lake’s water-quality measurements separately, 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. 2 stations on file (most recent sample 2023).
Fish Species (DNR-rated)
Lake Details
Max depth
58 ft
Surface area
113 acres
Public access
Yes
Listed by Wisconsin DNR
Lake Size & Watershed
Watershed (drainage) area
1 sq mi
HydroLAKES / HydroSHEDS
Shoreline
2.4 mi
HydroLAKES / HydroSHEDS
Elevation
1,588 ft
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Recreation & Access
- Long LakePublic
Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps
Stays via Stay22
Stays near Long Lake
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Fish Species
Click a species to see every lake where it is documented.
Fishing Long Lake
Water Quality Trend: Stable
Based on 6 years of monitoring (2020–2025).
Water clarity
Improving6 years
Phosphorus
Worsening+0.84 µg/L/yr6 years
EPA Impairment Status
Long Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).
Causes of impairment
Designated uses not supporting: Fish consumption.
Source: EPA ATTAINS assessment unit WI10007346 · Official waterbody report
Nearby Lakes in Oneida County
Frequently asked questions about Long Lake
Where is Long Lake?
- Long Lake is a lake in Oneida County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Long Lake?
- Long Lake in Oneida County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 10.5 ft visibility. Maximum depth: 58 ft. Surface area: 113 acres.
Is Long Lake safe to swim in?
- Nutrient and algae readings are not a swimming clearance. Long Lake is listed impaired under Clean Water Act §303(d) (IR 5) for mercury. Check local advisories before you swim.
How deep is Long Lake?
- Long Lake has a maximum depth of 58 feet. The lake covers 113 acres.
What fish are in Long Lake?
- Fish species found in Long Lake include Musky, Panfish, Largemouth Bass, Walleye. Long Lake is located in Oneida County, Wisconsin.
What did the DNR fisheries survey find at Long Lake?
- Wisconsin DNR lists Panfish as common on Long Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Long Lake’s water-quality measurements separately, 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 Long Lake?
- Long Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Long Lake. Public access is listed as yes.
Can I fish at Long Lake?
- Long Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Wisconsin's fish and wildlife agency, so check its current regulations before you go.
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Where this data comes from
12 measurements from 1 monitoring station, 2020–2023. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX12 samples · 2020–2023
Monitoring station identifiers (1)
EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from 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