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LakeQuality

Twin Bear Lake

NR
Not yet rated
19.5 ft clear · Oligotrophic · 157 acres
Limited DataOligotrophic

Twin Bear Lake in Bayfield County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 19.5 ft visibility. Maximum depth: 59 ft. Surface area: 157 acres.

Clarity
19.5 ft
Max depth
59 ft
Area
157 acres
Trend
Improving
Public access
Yes

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BEagle Lake17 ft clear · Bayfield CountyView →
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Why Twin Bear 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 Twin Bear 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, but not phosphorus and 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.

Twin Bear Lake is a 157-acre lake in Bayfield County, Wisconsin with a maximum depth of 59 feet. Overall water quality is improving over recent sampling years. The lake supports 6 documented fish species including Musky, Panfish, and Largemouth Bass. Public access is available with 1 public boat landing.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-08-29. Grade methodology: LakeGrade methodology.

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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 Hayward

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Water quality measurements for Twin Bear Lake

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

Crystal clear, you can see 19.5 ft down. Trophic State Index: 34.

MetricValueGrade
Water Clarity (Secchi Depth)19.5 ftNot graded
PhosphorusNo recent samples
Chlorophyll-a (Algae)No recent samples
Trophic State Index (TSI)34Oligotrophic

Low nutrients, clear water, excellent for swimming

Where to stay near Twin Bear Lake

Compare lakeside cabins, hotels, and vacation rentals near Twin Bear Lake in Bayfield 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 Twin Bear Lake

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Planning a whole trip? See where to stay at Wisconsin’s top lakes →

Lake Details

CharacteristicValue
Maximum Depth59 ft
Surface Area157 acres
Public AccessYes

Lake Size & Watershed

Watershed (drainage) area
19 sq mi
Shoreline
15.3 mi
Elevation
1,112 ft

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

Recreation & Access

1
Boat Landings
Yes
Public Access
  • Twin Bear County ParkPublic

Fish Species

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

Fishing Twin Bear 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.

Chinese Mystery SnailEurasian Water-MilfoilRusty Crayfish

WI DNR Lake Profile

Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1993. 1 station on file (most recent sample 2025).

Fish Species (DNR-rated)

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

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

MetricTrendChange/YearYears
Water Clarity Improving+0.714 m/yr6
Phosphorus Stable0 µg/L/yr7
See year-by-year chart →

Graded lakes near Twin Bear Lake

Twin Bear Lake has no grade, but these lakes within a short drive do.

Nearby Lakes in Bayfield County

Frequently asked questions about Twin Bear Lake

What is the water quality grade for Twin Bear Lake?

Twin Bear Lake in Bayfield County, Wisconsin is not rated for water quality — its monitoring record does not meet the evidence bar. Water clarity: 19.5 ft visibility. Maximum depth: 59 ft. Surface area: 157 acres.

Is Twin Bear Lake safe to swim in?

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

Twin Bear Lake has a maximum depth of 59 feet. The lake covers 157 acres.

What fish are in Twin Bear Lake?

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

Are there boat ramps on Twin Bear Lake?

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

Where this data comes from

20 measurements from 1 monitoring station, 2023–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

  • Wisconsin Department of Natural ResourcesWIDNR_WQX20 samples · 2023–2025
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