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Crab Lake

Vilas County, WisconsinMesotrophic

Crab Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Vilas County. 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.

The lake sits in the mesotrophic zone — the band where most well-managed Wisconsin lakes fall. 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. Crab Lake ranks 62 of 191 in Vilas County — solidly in the upper half of the local distribution.

No invasive species are currently listed at Crab Lake — the lake remains off the Wisconsin infested-waters roster. The state fisheries records do not list documented species for Crab Lake, which usually reflects a lack of formal fisheries survey work rather than an empty lake. Monitoring depth is thin here: the LakeGrade rubric is applied to a small number of sample years, and the grade will be revised as more data accumulates.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2024-08-31. Grade methodology: LakeGrade methodology.

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Swimming Safety

Excellent for swimming, crystal clear water with minimal algae

Water Quality Grade: A, Excellent

Good clarity, visible to about 11 ft. Phosphorus level: 12.6 µg/L. Trophic State Index: 42.

MetricValueGrade
Water Clarity (Secchi Depth)11 ftB
Phosphorus12.6 µg/LA
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)42Mesotrophic

Moderate nutrients, good water quality

Water Quality Trend: Improving

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

MetricTrendChange/YearYears
Water Clarity Improving+1 m/yr3
Phosphorus Improving-0.3 µg/L/yr4
See year-by-year chart →

Recreation & Access

1
Boat Landings
Yes
Public Access

Location

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County Ranking

Ranked #62 of 191 lakes in Vilas County

Nearby Lakes in Vilas County

DNR Reports & Resources

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

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

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

Most recent sample: 2024-08-31

Monitoring stations: 2

Where to stay near Crab Lake

Compare lakeside cabins, hotels, and vacation rentals near Crab Lake in Vilas County, Wisconsin — live availability and prices for your trip.

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