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LakeQuality

Bishop Lake

C
Grade C — Fair
Fair · #21 of 23 lakes in the county · 7 ft clear · Mesotrophic · 288 acres · from B
Mesotrophic

Bishop Lake in Forest County, Wisconsin has a water quality grade of C (Fair). Water clarity: 7 ft visibility. Phosphorus: 25.4 µg/L. Chlorophyll-a (algae): 3.5 µg/L. Maximum depth: 12 ft. Surface area: 288 acres.

Clarity
7 ft
Typical in August
71°F
Max depth
12 ft
Area
288 acres
Type
Mesotrophic
Trend
Declining
Public access
Yes

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AMole Lake8.5 ft clear · Forest CountyView →
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Bishop Lake is a 288-acre mesotrophic lake in Forest County, Wisconsin with a maximum depth of 12 feet. Water quality is graded C based on 2 sampling years through 2025. Overall water quality is declining over recent sampling years. The lake supports 3 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 1 public boat landing. Compared to the 22 other monitored lakes in Forest County, Bishop Lake ranks #21 for water quality.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-09-17. Grade methodology: LakeGrade methodology.

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Swimming Safety

Grade only

Moderate

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.

Generally safe for swimming, moderate water quality

Compare the safest swimming lakes near Rhinelander

Get alerts for Bishop Lake

Water Quality Grade: C (Fair)

Moderate clarity, visible to about 7 ft. Phosphorus level: 25.4 µg/L. Chlorophyll-a: 3.5 µg/L. Trophic State Index: 48.

MetricValueGrade
Water Clarity (Secchi Depth)7 ftNot graded
Phosphorus25.4 µg/LFair
Chlorophyll-a (Algae)3.5 µg/LGood
Trophic State Index (TSI)48Mesotrophic

Moderate nutrients, good water quality

Where to stay near Bishop Lake

Compare lakeside cabins, hotels, and vacation rentals near Bishop Lake in Forest 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 Bishop 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

Bishop Lake typically sits around 71°F at the surface in August. Summer average is about 71°F. Usually warmest in Jul (about 72°F) and coldest in Apr (about 44°F). These are typical values by month — not a live reading.

Jan
Feb
Mar
Apr
44°
May
58°
Jun
71°
Jul
72°
Aug
71°
Sep
66°
Oct
Nov
Dec

Typical surface water temperature by month, from 39 field readings (20242025) via the EPA Water Quality Portal. See the full Bishop Lake water temperature breakdown →

Lake Details

CharacteristicValue
Maximum Depth12 ft
Surface Area288 acres
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
8 sq mi
Shoreline
2.8 mi
Elevation
1,532 ft

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

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Bishop LakePublic

Fish Species

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

Fishing Bishop 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 Snail

WI DNR Lake Profile

Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1995. 1 station on file (most recent sample 2025).

Fish Species (DNR-rated)

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

DNR Reports & Resources

Wisconsin DNR Fisheries scientists publish multi-year survey reports for Bishop 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).

Based on 4 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-1.25 m/yr2
Phosphorus Stable+0.16 µg/L/yr4
Chlorophyll-a Stable+0.03 µg/L/yr4
See year-by-year chart →

County Ranking

Ranked #21 of 23 lakes in Forest County

Nearby Lakes With Higher Grades

Bishop Lake holds Grade C. 2 nearby lakes hold higher nutrient-and-algae grades — useful for a swim day, not a reason to skip lodging here.

See full comparison →

Nearby Lakes in Forest County

Frequently asked questions about Bishop Lake

What is the water quality grade for Bishop Lake?

Bishop Lake in Forest County, Wisconsin has a water quality grade of C (Fair). Water clarity: 7 ft visibility. Phosphorus: 25.4 µg/L. Chlorophyll-a (algae): 3.5 µg/L. Maximum depth: 12 ft. Surface area: 288 acres.

Is Bishop Lake safe to swim in?

Generally safe for swimming, moderate water quality. Bishop Lake has a water quality grade of C (Fair). Algae concentration (chlorophyll-a) is 3.5 µg/L. Always check local health department advisories before swimming.

What is the water temperature of Bishop Lake?

Bishop Lake typically sits around 71°F at the surface in August, from 39 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.

How deep is Bishop Lake?

Bishop Lake has a maximum depth of 12 feet. The lake covers 288 acres.

What fish are in Bishop Lake?

Fish species found in Bishop Lake include Panfish, Largemouth Bass, Northern Pike. Bishop Lake is located in Forest County, Wisconsin.

Are there boat ramps on Bishop Lake?

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

Where this data comes from

65 measurements from 2 monitoring stations, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Sokaogon Chippewa Community (Tribal)SOKAOGON_WQX43 samples · 2020–2025
  • Wisconsin Department of Natural ResourcesWIDNR_WQX22 samples · 2023–2025

Analytical methods

  • Phosphorus by Colorimetry
  • 4500 P E ~ Phosphorus in Water by Colorimetry- Ascorbic Acid Method
  • 4500 P F ~ Phosphorus in Water by Colorimetry Automated Ascorbic Acid Method
  • 200.7 M ~ ICP-AES For Trace Element Analysis
  • 10200 H ~ Chlorophyll a-b-c Determination
  • Turbidity by Nephelometry
Monitoring station identifiers (2)

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