Skip to main content
LakeQuality

Black Oak Lake

NR
Not yet rated
4.3 ft clear · Eutrophic · 56 acres
Limited DataEutrophic

Black Oak Lake in Langlade County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 4.3 ft visibility. Phosphorus: 29.1 µg/L. Maximum depth: 34 ft. Surface area: 56 acres.

Clarity
4.3 ft
Max depth
34 ft
Area
56 acres
Trend
Improving
Public access
Yes

Next lake in Langlade County

NRLower Clear Lake12 ft clear · Langlade CountyView →
Loading map…

Why Black Oak Lake has no grade

We grade a lake only when its monitoring record clears the evidence bar: 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 Black Oak 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 and phosphorus, but not 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.

Black Oak Lake is a 56-acre lake in Langlade County, Wisconsin with a maximum depth of 34 feet. 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.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2022-07-31. Grade methodology: LakeGrade methodology.

Watch Black Oak Lake water quality

Subscribe for LakeQuality updates by email. No spam, unsubscribe anytime.

Swimming Safety

Not rated

Limited data

Not rated for swimming — there is not enough monitoring data to judge this lake

Compare the safest swimming lakes near Rhinelander

Get alerts for Black Oak Lake

Water quality measurements for Black Oak Lake

These readings exist but do not meet the evidence bar for an A–F grade — see why.

Murky, only visible to about 4.3 ft. Phosphorus level: 29.1 µg/L. Trophic State Index: 54.

MetricValueGrade
Water Clarity (Secchi Depth)4.3 ftNot graded
Phosphorus29.1 µg/LNot graded
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)54Eutrophic

High nutrients, frequent algae, reduced clarity

Where to stay near Black Oak Lake

Compare lakeside cabins, hotels, and vacation rentals near Black Oak Lake in Langlade 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 Black Oak 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 →

Lake Details

CharacteristicValue
Maximum Depth34 ft
Surface Area56 acres
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
4 sq mi
Shoreline
2.4 mi
Elevation
1,637 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Recreation & Access

2
Boat Landings
Yes
Public Access
  • Long LakePublic
  • Black Oak LakePublic

Fish Species

Click a species to see every graded lake where it is documented.

Fishing Black Oak Lake

WI DNR Lake Profile

Authoritative data from the Wisconsin DNR LakePages. 1 station on file (most recent sample 2022).

Fish Species (DNR-rated)

Panfish(Present)Largemouth Bass(Present)Northern Pike(Present)

Based on 6 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+0.42 m/yr6
See year-by-year chart →

Graded lakes near Black Oak Lake

Black Oak Lake has no grade, but these lakes within a short drive do.

Nearby Lakes in Langlade County

Frequently asked questions about Black Oak Lake

What is the water quality grade for Black Oak Lake?

Black Oak Lake in Langlade County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 4.3 ft visibility. Phosphorus: 29.1 µg/L. Maximum depth: 34 ft. Surface area: 56 acres.

Is Black Oak Lake safe to swim in?

Not rated for swimming — there is not enough monitoring data to judge this lake. Black Oak 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 Black Oak Lake?

Black Oak Lake has a maximum depth of 34 feet. The lake covers 56 acres.

What fish are in Black Oak Lake?

Fish species found in Black Oak Lake include Panfish, Largemouth Bass, Northern Pike. Black Oak Lake is located in Langlade County, Wisconsin.

Are there boat ramps on Black Oak Lake?

Black Oak Lake has 2 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Long Lake, Black Oak Lake. Public access is listed as yes.

Where this data comes from

14 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 ResourcesWIDNR_WQX14 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

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