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Ranch Lake

Oconto County, WisconsinMesotrophic

Ranch Lake earns an A — water clarity, phosphorus, and chlorophyll-a all rate among the best monitored waters in Oconto County. The three sub-grades — clarity, phosphorus, and chlorophyll-a — track close together, so no single parameter is dragging the average.

The lake sits in the mesotrophic zone — the band where most well-managed Wisconsin lakes fall. A maximum depth of 44 ft puts Ranch Lake in the middle of Wisconsin's depth distribution. Ranch Lake is small — 52 acres alongside partial shoreline records — which makes it sensitive to even modest changes in watershed runoff or recreational pressure. Ranch Lake ranks 27 of 62 in Oconto County — solidly in the upper half of the local distribution.

Ranch Lake has at least one documented invasive species (Purple Loosestrife), so boaters and anglers should observe clean-drain-dry steps when leaving the lake. Bass fishing is part of the appeal: the species list runs to 3, anchored by largemouth and/or smallmouth bass. Public access is available — the lake is on the Wisconsin DNR public-access list. 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 2025-08-06. 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 12.5 ft. Phosphorus level: 14.4 µg/L. Trophic State Index: 42.

MetricValueGrade
Water Clarity (Secchi Depth)12.5 ftB
Phosphorus14.4 µg/LA
Chlorophyll-a (Algae)No data
Trophic State Index (TSI)42Mesotrophic

Moderate nutrients, good water quality

Lake Details

CharacteristicValue
Maximum Depth44 ft
Surface Area52 acres
Public AccessYes

Fish Species

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

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

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

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

Invasive & Introduced Species

Red chips are ecologically harmful invasive species. Gray chips are stocked or introduced fish that aren't a current ecological concern.

Purple Loosestrife

Water Quality Trend: Improving

Based on 6 years of monitoring data (2020-2025).

MetricTrendChange/YearYears
Water Clarity Improving+1.407 m/yr6
Phosphorus Improving-2.45 µg/L/yr3
See year-by-year chart →

Recreation & Access

10
Boat Landings
Yes
Public Access

Location

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County Ranking

Ranked #27 of 62 lakes in Oconto County

Nearby Lakes in Oconto County

WI DNR Lake Profile

Authoritative data from the Wisconsin DNR LakePages. Monitored by volunteers since 1987. 1 station on file (most recent sample 2025).

DNR Assessment
Excellent · Deep Seepage lake
Trophic State Index 40 (oligotrophic) · 5-year average

Fish Species (DNR-rated)

Panfish(Present)Largemouth Bass(Present)Northern Pike(Present)

DNR Reports & Resources

Wisconsin DNR Fisheries scientists publish multi-year survey reports for Ranch Lake covering fish populations, stocking, water quality, and management. 4 reports on file.

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

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

Most recent sample: 2025-08-06

Monitoring stations: 1

Where to stay near Ranch Lake

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

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