Mildred Lake
Mildred Lake in Oneida County, Wisconsin has a water quality grade of B (Good). Water clarity: 18 ft visibility. Phosphorus: 12.3 µg/L. Maximum depth: 45 ft. Surface area: 168 acres.
Wisconsin DNR lists Largemouth Bass as common on Mildred Lake. DNR survey details →
- Clarity
- 18 ft
- Typical in August
- 71°F
- Max depth
- 45 ft
- Area
- 168 acres
- Type
- Oligotrophic
- Trend
- ↓ Declining
- Public access
- Yes
Next lake in Oneida County
Swipe left or right on this bar to open the next or previous lake.
Mildred Lake is a 168-acre cold, clear oligotrophic lake in Oneida County, Wisconsin with a maximum depth of 45 feet. Water quality is graded B based on 1 sampling years through 2026. Overall water quality is declining over recent sampling years. The lake supports 4 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available. Compared to the 66 other monitored lakes in Oneida County, Mildred Lake ranks #20 for water quality.
Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-29. Grade methodology: LakeQuality methodology.
Watch Mildred Lake water quality
Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.
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)
Crystal clear, you can see 18 ft down. Phosphorus level: 12.3 µg/L. Trophic State Index: 38.
| Metric | Value | Grade |
|---|---|---|
| Water Clarity (Secchi Depth) | 18 ft | Not graded |
| Phosphorus | 12.3 µg/L | Good |
| Chlorophyll-a (Algae) | No recent samples | |
| Trophic State Index (TSI) | 38 | Oligotrophic |
Low nutrients, clear water, excellent for swimming
Where to stay near Mildred Lake
Compare lakeside cabins, hotels, and vacation rentals near Mildred 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 Mildred 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 →
Water Temperature
Mildred Lake typically sits around 71°F at the surface in August. Summer average is about 73°F. Usually warmest in Jul (about 75°F) and coldest in Aug (about 71°F). These are typical values by month — not a live reading.
Typical surface water temperature by month, from 9 field readings (2024–2025) via the EPA Water Quality Portal. See the full Mildred Lake water temperature breakdown →
Wisconsin DNR lists Largemouth Bass as common on Mildred Lake.
A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Mildred Lake B from EPA Water Quality Portal chemistry, and the water-quality trend over 7 years of monitoring is declining. 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. Monitored by volunteers since 1992. 1 station on file (most recent sample 2025).
Fish Species (DNR-rated)
Lake Details
| Characteristic | Value |
|---|---|
| Maximum Depth | 45 ft |
| Surface Area | 168 acres |
| Public Access | Yes |
Lake Size & Watershed
Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).
Fish Species
Click a species to see every graded lake where it is documented.
Fishing Mildred 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: ↓ Declining
Based on 7 years of monitoring data (2020-2025).
| Metric | Trend | Change/Year | Years |
|---|---|---|---|
| Water Clarity | ↓ Declining | -0.598 m/yr | 7 |
| Phosphorus | ↓ Declining | +0.43 µg/L/yr | 7 |
County Ranking
Ranked #20 of 67 lakes in Oneida County
Nearby Lakes in Oneida County
Frequently asked questions about Mildred Lake
Where is Mildred Lake?
- Mildred Lake is a lake in Oneida County, Wisconsin. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.
What is the water quality grade for Mildred Lake?
- Mildred Lake in Oneida County, Wisconsin has a water quality grade of B (Good). Water clarity: 18 ft visibility. Phosphorus: 12.3 µg/L. Maximum depth: 45 ft. Surface area: 168 acres.
Is Mildred Lake safe to swim in?
- Good for swimming, clear water with low algae levels. Mildred Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.
What is the water temperature of Mildred Lake?
- Mildred Lake typically sits around 71°F at the surface in August, from 9 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Mildred Lake?
- Mildred Lake has a maximum depth of 45 feet. The lake covers 168 acres.
What fish are in Mildred Lake?
- Fish species found in Mildred Lake include Musky, Panfish, Largemouth Bass, Walleye. Mildred Lake is located in Oneida County, Wisconsin.
What did the DNR fisheries survey find at Mildred Lake?
- Wisconsin DNR lists Largemouth Bass as common on Mildred Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Mildred Lake B from EPA Water Quality Portal chemistry, and the water-quality trend over 7 years of monitoring is declining. Catch rate is not a swim clearance and is not a weekly bite report.
Explore Mildred 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
Low nutrients, clear water, excellent for swimming
Wisconsin's cleanest and most-polluted lakes, ranked
More Wisconsin Lake Rankings
Other Grade B Lakes in Wisconsin
Oligotrophic Lakes in Wisconsin
Where this data comes from
34 measurements from 1 monitoring station, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.
Collected and reported by
- Wisconsin Department of Natural Resources
WIDNR_WQX34 samples · 2020–2026
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
Lake size & watershed from HydroLAKES (HydroSHEDS)
Fish and recreation data from Wisconsin DNR Lakes