Third Lake
Third Lake in Oneida County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 3.5 ft visibility. Maximum depth: 14 ft. Surface area: 97 acres.
Wisconsin DNR lists Panfish as common on Third Lake. DNR survey details →
- Clarity
- 3.5 ft
- Max depth
- 14 ft
- Area
- 97 acres
- Trend
- → Stable
Next lake in Oneida County
Swipe left or right on this bar to open the next or previous lake.
Why Third 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 Third Lake, the only measurement available is water clarity, which is not a water-quality indicator on its own — EPA's National Lakes Assessment does not grade clarity. Sampling here has recorded water clarity, but not phosphorus and 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.
Third Lake is a 97-acre lake in Oneida County, Wisconsin with a maximum depth of 14 feet. Water clarity is declining over recent sampling years. The lake supports 6 documented fish species including Musky, Panfish, and Largemouth Bass.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2023-08-21. Grade methodology: LakeQuality methodology.
Watch Third Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
Swimming Safety
Not ratedLimited data
Not rated for swimming — there is not enough monitoring data to judge this lake
Water quality measurements for Third Lake
These readings exist but are not enough for an A–F grade — see why.
Murky, only visible to about 3.5 ft. Trophic State Index: 59.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 3.5 ft | Not graded |
| Phosphorus | No recent samples | |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 59 | Eutrophic |
High nutrients, frequent algae, reduced clarity
Where to stay near Third Lake
Compare lakeside cabins, hotels, and vacation rentals near Third Lake in Oneida 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 Third Lake
Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.
Planning a whole trip? See where to stay at Wisconsin’s top lakes →
Wisconsin DNR lists Panfish as common on Third 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 Third Lake — official chemistry is on file, not a letter, and the water-quality trend over 7 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 2024).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 14 ft |
| Surface Area | 97 acres |
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Third 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 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.201 m/yr | 7 |
| Phosphorus | ↑ Improving | -0.79 µg/L/yr | 7 |
EPA Impairment Status
Third 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 WI10007459 · Official waterbody report
Graded lakes near Third Lake
Third Lake has no grade, but these lakes within a short drive do.
Nearby Lakes in Oneida County
Frequently asked questions about Third Lake
Where is Third Lake?
- Third Lake is a lake in Oneida 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 Third Lake?
- Third Lake in Oneida County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 3.5 ft visibility. Maximum depth: 14 ft. Surface area: 97 acres.
Is Third Lake safe to swim in?
- Not rated for swimming — there is not enough monitoring data to judge this lake. Third 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 Third Lake?
- Third Lake has a maximum depth of 14 feet. The lake covers 97 acres.
What fish are in Third Lake?
- Fish species found in Third Lake include Musky, Panfish, Largemouth Bass, Smallmouth Bass, Northern Pike, Walleye. Third Lake is located in Oneida County, Wisconsin.
What did the DNR fisheries survey find at Third Lake?
- Wisconsin DNR lists Panfish as common on Third 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 Third Lake — official chemistry is on file, not a letter, and the water-quality trend over 7 years of monitoring is stable. Catch rate is not a swim clearance and is not a weekly bite report.
Explore Third Lake across LakeQuality
Fish species and top-graded lakes across Wisconsin
Fish species and best lakes in Oneida County
Species activity outlook by water temperature and season
Top lakes and where to stay in the Northwoods Wisconsin area
Top lakes and where to stay in the Minocqua Chain area
Where to stay at Wisconsin's top lakes, each with its grade
Lakes in the Wisconsin River Watershed, ranked by water quality
Wisconsin's cleanest and most-polluted lakes, ranked
More Wisconsin Lake Rankings
Other Lakes in Wisconsin
Eutrophic Lakes in Wisconsin
Where this data comes from
18 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_WQX18 samples · 2020–2023
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