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LakeQuality
C

Bear Lake

Bayfield County, WisconsinEutrophic

Bear Lake earns a C — middle-of-the-pack water quality, with one or two parameters dragging the average down from a stronger grade. Sub-grades cluster within a single letter of each other, which usually means the lake is in stable trophic balance rather than fighting one specific stressor.

Eutrophic conditions are the baseline here: clarity drops noticeably in late summer, and dissolved oxygen near the bottom can become a concern. The lake's maximum depth is not yet documented in state morphometric records — context for its physical structure remains limited. The lake's surface area is not consistently recorded across state datasets — physical context remains partial. Bear Lake ranks 54 of 55 in Bayfield County — at the lower end of the locally monitored distribution.

Bear Lake has no invasive species recorded in Wisconsin state databases as of 2025, though prevention practices still apply at all access points. The state fisheries records do not list documented species for Bear Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. 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 2025-09-09. Grade methodology: LakeGrade methodology.

Swimming Safety

Generally safe for swimming, moderate water quality

Water Quality Grade: C, Fair

Murky, only visible to about 6.6 ft. Phosphorus level: 48.6 µg/L. Trophic State Index: 55.

MetricValueGrade
Water Clarity (Secchi Depth)6.6 ftD
Phosphorus48.6 µg/LC
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)55Eutrophic

High nutrients, frequent algae, reduced clarity

Water Quality Trend: Declining

Based on 3 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-1.98 m/yr3
Phosphorus Declining+12.73 µg/L/yr2
See year-by-year chart →

Location

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County Ranking

Ranked #54 of 55 lakes in Bayfield County

Cleaner Lakes Within 30 Miles

Bear Lake holds Grade C. 2 nearby lakes hold higher grades.

See full comparison →

Nearby Lakes in Bayfield County

Eutrophic Lakes in Wisconsin

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Most recent sample: 2025-09-09

Monitoring stations: 1