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B

Long Lake

Oneida County, WisconsinLimited DataMesotrophic

On the LakeGrade scale Long Lake grades a B, with clarity at 11.3 ft and phosphorus readings still being added placing it above the Wisconsin median. 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.

A TSI near 42 places Long Lake in the mesotrophic band — moderate productivity, with seasonal swings between clearer spring water and richer late-summer conditions. Long Lake reaches 31 ft at its deepest point — typical for Wisconsin mid-sized lakes, with seasonal stratification but limited cold-water refuge. At 108 acres, Long Lake fits the Wisconsin median for monitored lakes, with partial shoreline records. Long Lake ranks 42 of 134 in Oneida County — solidly in the upper half of the local distribution.

No invasive species are currently listed at Long Lake — the lake remains off the Wisconsin infested-waters roster. Bass fishing is part of the appeal: the species list runs to 2, anchored by largemouth and/or smallmouth bass. 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 2022-08-10. Grade methodology: LakeGrade methodology.

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Swimming Safety

Good for swimming, clear water with low algae levels

Water Quality Grade: B, Good

Good clarity, visible to about 11.3 ft. Trophic State Index: 42.

MetricValueGrade
Water Clarity (Secchi Depth)11.3 ftB
PhosphorusNo data
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)42Mesotrophic

Moderate nutrients, good water quality

Lake Details

CharacteristicValue
Maximum Depth31 ft
Surface Area108 acres

Fish Species

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

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

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

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

Water Quality Trend: Declining

Based on 2 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Declining-2.62 m/yr2

Location

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County Ranking

Ranked #42 of 134 lakes in Oneida County

Cleaner Lakes Within 30 Miles

Long Lake holds Grade B. One nearby lake has a higher grade.

Nearby Lakes in Oneida County

WI DNR Lake Profile

Authoritative data from the Wisconsin DNR LakePages. 1 station on file (most recent sample 2022).

Fish Species (DNR-rated)

Panfish(Abundant)Largemouth Bass(Common)

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: 2022-08-10

Monitoring stations: 1

Where to stay near Long Lake

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

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