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LakeQuality

Plum Lake

B
Grade B — Good
Good · #7 of 103 lakes in the county · 14.2 ft clear · Oligotrophic · 1,057 acres · from A
Oligotrophic

Plum Lake in Vilas County, Wisconsin has a water quality grade of B (Good). Water clarity: 14.2 ft visibility. Phosphorus: 13 µg/L. Maximum depth: 57 ft. Surface area: 1057 acres.

Wisconsin DNR lists Musky as common on Plum Lake. DNR survey details →

Clarity
14.2 ft
Typical in August
72°F
Max depth
57 ft
Area
1,057 acres
Type
Oligotrophic
Trend
Declining
Public access
Yes

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Plum Lake is a 1,057-acre cold, clear oligotrophic lake in Vilas County, Wisconsin with a maximum depth of 57 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 6 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available with 3 public boat landings. Compared to the 102 other monitored lakes in Vilas County, Plum Lake ranks #7 for water quality.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-07-04. Grade methodology: LakeQuality 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 Minocqua

Get alerts for Plum Lake

Water Quality Grade: B (Good)

Good clarity, visible to about 14.2 ft. Phosphorus level: 13 µg/L. Trophic State Index: 40.

MetricValueGrade
Water Clarity (Secchi Depth)14.2 ftNot graded
Phosphorus13 µg/LGood
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)40Oligotrophic

Low nutrients, clear water, excellent for swimming

Where to stay near Plum Lake

Compare lakeside cabins, hotels, and vacation rentals near Plum 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 Plum 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

Plum Lake typically sits around 72°F at the surface in August. Summer average is about 71°F. Usually warmest in Jul (about 75°F) and coldest in Jun (about 67°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
May
Jun
67°
Jul
75°
Aug
72°
Sep
Oct
Nov
Dec

Typical surface water temperature by month, from 17 field readings (20242026) via the EPA Water Quality Portal. See the full Plum Lake water temperature breakdown →

Blue-Green Algae (Cyanobacteria)

No current satellite reading

There’s no recent EPA CyAN cyanobacteria estimate for Plum Lake — clouds, ice, or an off-season gap in coverage. The most recent reading was high (619,441 cells/mL) on November 22, 2025.

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

DNR fisheries survey

Wisconsin DNR lists Musky as common on Plum Lake.

A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Plum 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 1990. 12 stations on file (most recent sample 2025).

DNR Assessment
Reported
Trophic State Index 40 (oligotrophic) · 5-year average

Fish Species (DNR-rated)

Musky(Common)Panfish(Common)Walleye(Common)Largemouth Bass(Present)Smallmouth Bass(Present)Northern Pike(Present)

DNR Reports & Resources

Wisconsin DNR Fisheries scientists publish multi-year survey reports for Plum Lake covering fish populations, stocking, water quality, and management. 1 report on file.

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

Lake Details

CharacteristicValue
Maximum Depth57 ft
Surface Area1,057 acres
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
29 sq mi
Shoreline
13.3 mi
Elevation
1,631 ft

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

Recreation & Access

3
Boat Landings
Yes
Public Access
1
Campgrounds
  • Plum LakePublic
  • Plum LakePublic
  • West Plum LakePublic

Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps

Public campgrounds near Plum Lake

  • Plum Lake Campground2.2 km

Nearest public campgrounds in the USGS National Map inventory, within about 3 miles. An empty list means USGS records no campground that close, which is not the same as camping being unavailable. Where the source gives an official reservation link, it is used; the cabin and hotel search does not cover campsites. More camping lakes

Fish Species

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

Fishing Plum 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 SnailHybrid Eurasian / Northern Water-MilfoilRusty CrayfishSpiny Waterflea

Based on 7 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Stable-0.232 m/yr7
Phosphorus Declining+2.56 µg/L/yr5
See year-by-year chart →

County Ranking

Ranked #7 of 103 lakes in Vilas County

Nearby Lakes in Vilas County

Frequently asked questions about Plum Lake

Where is Plum Lake?

Plum 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 Plum Lake?

Plum Lake in Vilas County, Wisconsin has a water quality grade of B (Good). Water clarity: 14.2 ft visibility. Phosphorus: 13 µg/L. Maximum depth: 57 ft. Surface area: 1057 acres.

Is Plum Lake safe to swim in?

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

What is the water temperature of Plum Lake?

Plum Lake typically sits around 72°F at the surface in August, from 17 EPA Water Quality Portal field readings (2024–2026). That is a typical value for the month, not a live reading.

How deep is Plum Lake?

Plum Lake has a maximum depth of 57 feet. The lake covers 1057 acres.

What fish are in Plum Lake?

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

What did the DNR fisheries survey find at Plum Lake?

Wisconsin DNR lists Musky as common on Plum Lake. A DNR fisheries survey reports fish abundance and catch rates, not a water-quality grade. LakeQuality grades Plum 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.

Does Plum Lake have blue-green algae?

There is no recent EPA CyAN cyanobacteria estimate for Plum Lake (clouds, ice, or an off-season gap). The most recent reading was high (619,441 cells/mL). Blue-green algae can appear and clear within days, so check Wisconsin's current advisory before swimming.

Are there boat ramps on Plum Lake?

Plum Lake has 3 documented boat landings in the USGS National Boat Ramps inventory. Named access points include Plum Lake, Plum Lake, West Plum Lake. Public access is listed as yes.

Are there campgrounds on Plum Lake?

Plum Lake has 1 public campground from USGS The National Map within 5 km, including Plum Lake Campground. This is a location join, not a booking. Cabins and hotels are listed separately; campsite reservations use the official link when the source provides one.

Where this data comes from

77 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 ResourcesWIDNR_WQX77 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

Named boat-access points from the USGS National Boat Ramps inventory

Public campgrounds from USGS The National Map Structures, within about 3 miles