Skip to main content
LakeQuality
A

Bear Lake

Oneida County, WisconsinOligotrophic

On the LakeGrade rubric, Bear Lake pulls an A: clarity at 27.7 ft and 18 µg/L of phosphorus put it in the top bracket for Wisconsin. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

Trophically, Bear Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. Bear Lake reaches 20 ft at its deepest point — typical for Wisconsin mid-sized lakes, with seasonal stratification but limited cold-water refuge. At 295 acres, Bear Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Bear Lake ranks 8 of 140 in Oneida County, putting it in the upper tier of locally monitored lakes.

Bear Lake has at least one documented invasive species (Chinese Mystery Snail), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. Walleye are documented at Bear Lake, one of 5 fish species on record for the lake. A documented public access point at Bear Lake makes the lake usable for shore fishing, paddle craft, and trailered boats. The grade is based on limited monitoring — fewer than three independent measurement years contribute, so future updates may shift the letter.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-11-10. Grade methodology: LakeGrade methodology.

Swimming Safety

Excellent for swimming, crystal clear water with minimal algae

Water Quality Grade: A, Excellent

Crystal clear, you can see 27.7 ft down. Phosphorus level: 18 µg/L. Trophic State Index: 38.

MetricValueGrade
Water Clarity (Secchi Depth)27.7 ftA
Phosphorus18 µg/LA
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)38Oligotrophic

Low nutrients, clear water, excellent for swimming

Lake Details

CharacteristicValue
Maximum Depth20 ft
Surface Area295 acres
Public AccessYes

Fish Species

Click a species to see all Wisconsin and Minnesota lakes where it is found.

→ Best fishing times for Bear Lake (14-day solunar calendar)

→ Is it safe to eat fish from Bear Lake? (mercury & PFAS guide)

Bear Lake fishing regulations (limits, seasons, special rules)

Invasive Species

Chinese Mystery SnailPurple LoosestrifeRusty Crayfish

Water Quality Trend: Declining

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

MetricTrendChange/YearYears
Water Clarity Declining-0.449 m/yr7
Phosphorus Stable+0.28 µg/L/yr6
See year-by-year chart →

Recreation & Access

1
Boat Landings
Yes
Public Access

Location

Loading map…

County Ranking

Ranked #8 of 140 lakes in Oneida County

Nearby Lakes in Oneida County

WI DNR Lake Profile

Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1986. 1 station on file (most recent sample 2025).

DNR Assessment
Excellent · Shallow Headwater lake
Trophic State Index 50 (mesotrophic) · 5-year average

Fish Species (DNR-rated)

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

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Fish and recreation data from Wisconsin DNR Lakes

Most recent sample: 2025-11-10

Monitoring stations: 2