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LakeQuality
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Little Rock Lake

Vilas County, WisconsinLimited DataOligotrophic

On the LakeGrade rubric, Little Rock Lake pulls an A: clarity readings still being added and 8 µg/L of phosphorus put it in the top bracket for Wisconsin. Clarity, phosphorus, and chlorophyll-a all rate similarly, so there is no obvious single lever to pull on watershed management.

Trophically, Little Rock Lake reads as oligotrophic — nutrient-poor, clear, and ecologically more sensitive to disturbance than richer lakes. 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. Within Vilas County's 202 graded lakes, Little Rock Lake ranks 147 — below the local median, though not at the bottom.

Little Rock 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 Little Rock 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 2025-10-30. Grade methodology: LakeGrade methodology.

Swimming Safety

Excellent for swimming, crystal clear water with minimal algae

Water Quality Grade: A, Excellent

No clarity data. Phosphorus level: 8.3 µg/L. Trophic State Index: 35.

MetricValueGrade
Water Clarity (Secchi Depth)No data
Phosphorus8.3 µg/LA
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)35Oligotrophic

Low nutrients, clear water, excellent for swimming

Water Quality Trend: Improving

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

MetricTrendChange/YearYears
Phosphorus Improving-5.2 µg/L/yr3
See year-by-year chart →

Location

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County Ranking

Ranked #147 of 202 lakes in Vilas County

Nearby Lakes in Vilas County

Data Sources

Water quality data from the EPA Water Quality Portal

Grading methodology based on Metropolitan Council standards

Most recent sample: 2025-10-30

Monitoring stations: 2