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LakeQuality

Pioneer Lake

B
Grade B — Good
Good · #9 of 103 lakes in the county · 9.5 ft clear · Mesotrophic · 429 acres
Mesotrophic

Pioneer Lake in Vilas County, Wisconsin has a water quality grade of B (Good). Water clarity: 9.5 ft visibility. Phosphorus: 15.2 µg/L. Maximum depth: 27 ft. Surface area: 429 acres.

Clarity
9.5 ft
Typical in August
71°F
Max depth
27 ft
Area
429 acres
Type
Mesotrophic
Trend
Improving
Public access
Yes

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Pioneer Lake is a 429-acre mesotrophic lake in Vilas County, Wisconsin with a maximum depth of 27 feet. Water quality is graded B based on 1 sampling years through 2025. Overall water quality is improving over recent sampling years. The lake supports 5 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available with 1 public boat landing. Compared to the 102 other monitored lakes in Vilas County, Pioneer Lake ranks #9 for water quality.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-10-13. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Low 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

Compare the safest swimming lakes near Eagle River

Get alerts for Pioneer Lake

Water Quality Grade: B (Good)

Moderate clarity, visible to about 9.5 ft. Phosphorus level: 15.2 µg/L. Trophic State Index: 44.

MetricValueGrade
Water Clarity (Secchi Depth)9.5 ftNot graded
Phosphorus15.2 µg/LGood
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)44Mesotrophic

Moderate nutrients, good water quality

Where to stay near Pioneer Lake

Compare lakeside cabins, hotels, and vacation rentals near Pioneer Lake in Vilas 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 Pioneer 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

Pioneer Lake typically sits around 71°F at the surface in August. Summer average is about 71°F. Usually warmest in Jul (about 74°F) and coldest in May (about 58°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
58°
Jun
67°
Jul
74°
Aug
71°
Sep
67°
Oct
59°
Nov
Dec

Typical surface water temperature by month, from 47 field readings (20242025) via the EPA Water Quality Portal. See the full Pioneer Lake water temperature breakdown →

Blue-Green Algae (Cyanobacteria)

No current satellite reading

There’s no recent EPA CyAN cyanobacteria estimate for Pioneer Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was moderate (32,211 cells/mL) on May 23, 2026.

Blue-green algae can appear and clear within days, so check your state’s current advisory before swimming. EPA CyAN ↗

Lake Details

CharacteristicValue
Maximum Depth27 ft
Surface Area429 acres
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
33 sq mi
Shoreline
3.7 mi
Elevation
1,663 ft

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

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Pioneer LakePublic

Named access points from the USGS National Boat Ramps inventory, snapped within 5 km. More lakes with boat ramps

Fish Species

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

Fishing Pioneer 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.

Banded Mystery SnailChinese Mystery SnailRusty Crayfish

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

MetricTrendChange/YearYears
Water Clarity Stable-0.039 m/yr6
Phosphorus Improving-0.9 µg/L/yr3
See year-by-year chart →

EPA Impairment Status

Pioneer Lake is officially listed as impaired under Clean Water Act §303(d) in the 2024 EPA reporting cycle (IR category 5).

Causes of impairment

Nutrients (phosphorus, nitrogen)

Source: EPA ATTAINS assessment unit WI10007721 · Official waterbody report · Matched by proximity (2.85 km)

County Ranking

Ranked #9 of 103 lakes in Vilas County

Nearby Lakes in Vilas County

Frequently asked questions about Pioneer Lake

Where is Pioneer Lake?

Pioneer Lake is a lake in Vilas County, Wisconsin. LakeQuality grades it B for nutrients and algae. The letter is not a swimming clearance.

What is the water quality grade for Pioneer Lake?

Pioneer Lake in Vilas County, Wisconsin has a water quality grade of B (Good). Water clarity: 9.5 ft visibility. Phosphorus: 15.2 µg/L. Maximum depth: 27 ft. Surface area: 429 acres.

Is Pioneer Lake safe to swim in?

Good for swimming, clear water with low algae levels. Pioneer Lake has a water quality grade of B (Good). Always check local health department advisories before swimming.

What is the water temperature of Pioneer Lake?

Pioneer Lake typically sits around 71°F at the surface in August, from 47 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.

How deep is Pioneer Lake?

Pioneer Lake has a maximum depth of 27 feet. The lake covers 429 acres.

What fish are in Pioneer Lake?

Fish species found in Pioneer Lake include Musky, Panfish, Largemouth Bass, Northern Pike, Walleye. Pioneer Lake is located in Vilas County, Wisconsin.

Does Pioneer Lake have blue-green algae?

There is no recent EPA CyAN cyanobacteria estimate for Pioneer Lake (clouds, ice, or an off-season gap). The most recent reading was moderate (32,211 cells/mL). Blue-green algae can appear and clear within days, so check Wisconsin's current advisory before swimming.

Are there boat ramps on Pioneer Lake?

Pioneer Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Pioneer Lake. Public access is listed as yes.

Where this data comes from

127 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Wisconsin Department of Natural ResourcesWIDNR_WQX127 samples · 2020–2025

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