Ranch Lake is a lake in Oconto County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.

What is the water temperature of Ranch Lake?

Ranch Lake typically sits around 78°F at the surface in July, from 9 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.

How deep is Ranch Lake?

Ranch Lake has a maximum depth of 44 feet. The lake covers 52 acres.

What fish are in Ranch Lake?

Fish species found in Ranch Lake include Panfish, Largemouth Bass, Northern Pike. Ranch Lake is located in Oconto County, Wisconsin.

Are there boat ramps on Ranch Lake?

Ranch Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Ranch Lake. Public access is listed as yes.

Can I fish at Ranch Lake?

Ranch Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Wisconsin's fish and wildlife agency, so check its current regulations before you go.

Ranch Lake

Oconto County, Wisconsin52 acresView map Directions

Wisconsin DNR publishes the water-quality measurements for Ranch Lake. Here is what has been measured.

Clarity

12.5 ft

Clearer than most

Secchi · sampled 2025

Phosphorus

14.4 µg/L

Typical for Wisconsin

Measured by Wisconsin DNR

Water temp

~78°F

Typical for Jul · EPA WQP

Max depth

44 ft

Bathymetric survey

Area

52 acres

Surface area

Type

Mesotrophic

Trophic class

Mesotrophic
Purple Loosestrife
44 ft max depth
Public access
Limited data

See the measurements Directions Where to stay

Ranch Lake in Oconto County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 12.5 ft visibility. Phosphorus: 14.4 µg/L. Maximum depth: 44 ft. Surface area: 52 acres.

Wisconsin DNR lists Panfish as present on Ranch Lake. DNR survey details →

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Ranch Lake is a 52-acre mesotrophic lake in Oconto County, Wisconsin with a maximum depth of 44 feet. Overall water quality is improving over recent sampling years. The lake supports 3 documented fish species including Panfish, Largemouth Bass, and Northern Pike. Public access is available with 1 public boat landing. Compared to the 38 other monitored lakes in Oconto County, Ranch Lake ranks #18 for water quality.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2025-08-06. Methodology: how these readings are compared.

What Ranch Lake is good for

From access and monitoring records, not editorial picks.

Clear water12.5 ft of visibility
Boat launch1 documented ramp
Fishing3 species recorded
Deep water44 ft surveyed max depth

Swimming conditions

Readings only

Limited data

Based on clarity and algae readings from past sampling — there is no live water temperature and a current cyanobacteria reading for this lake. Check your state or county health department before you swim.

Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.

Whether Ranch Lake is safe to swim in today is a call for the Wisconsin Department of Natural Resources and the county health department, who post current advisories. LakeQuality does not issue swimming clearances.

Compare swimming lakes near Green Bay →

Get alerts for Ranch Lake →

Water quality measurements for Ranch Lake

These are the measurements Wisconsin DNR publishes for Ranch Lake, shown as reported. The condition class beside each reading is the EPA National Lakes Assessment class for this lake’s ecoregion.

Good clarity, visible to about 12.5 ft. Phosphorus 14.4 µg/L. TSI 42.

Water quality readings
Measure	Reading	Where it sits
Water clarity (Secchi depth)	12.5ft	Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer.
Total phosphorus	14.4µg/L	Good GoodFairPoor
Chlorophyll-a (algae)		No reading The green pigment in algae — a direct measure of how much algae is in the water.
Trophic state (TSI)Carlson's 0–100 index of how much algae a lake can support, from clarity, phosphorus and chlorophyll-a.	42	Mesotrophic OligotrophicMesotrophicEutrophicHypereutrophic

Moderate nutrients, good water quality

Ask about Ranch Lake

Answers come straight from the public measurements and survey records on this page.

Water Temperature

Ranch Lake typically sits around 78°F at the surface in July. Summer average is about 75°F. Usually warmest in Jul (about 78°F) and coldest in May (about 59°F). These are typical values by month — not a live reading.

Jan

Feb

Mar

Apr

59°

May

71°

Jun

78°

Jul

Aug

Sep

Oct

Nov

Dec

Column height runs from this lake’s coldest month (59°F) to its warmest (78°F).

Typical surface water temperature by month, from 9 field readings (2024–2025) via the EPA Water Quality Portal. See the full Ranch Lake water temperature breakdown →

DNR fisheries survey

Wisconsin DNR lists Panfish as present on Ranch Lake.

A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Ranch Lake’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.

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)

Contour map (PDF) →Full WI DNR LakePage →Water quality stations →

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.

These links open on the official state DNR websites (Wisconsin DNR survey PDFs · Minnesota DNR LakeFinder).

2018
First South Branch Oconto River trend survey, 2018
Fisheries Survey · WI DNR · 2018 (PDF)
2017
South Branch Oconto River information sheet 2017
Fisheries Survey · WI DNR · 2017 (PDF)
2016
First South Branch Oconto River fisheries information sheet 2016
Fisheries Survey · WI DNR · 2016 (PDF)
2015
South Branch Oconto River fisheries information sheet 2015
Fisheries Survey · WI DNR · 2015 (PDF)

Lake Details

Max depth

44 ft

Surface area

52 acres

Public access

Yes

Listed by Wisconsin DNR

Lake Size & Watershed

Watershed (drainage) area

0 sq mi

HydroLAKES / HydroSHEDS

Shoreline

1.2 mi

HydroLAKES / HydroSHEDS

Elevation

876 ft

Size, shoreline, and watershed area from HydroLAKES (HydroSHEDS).

Recreation & Access

Boat Landings

Yes

Public Access

Ranch LakePublic

Named access points in the USGS National Boat Ramps inventory, within about 3 miles. More lakes with boat ramps

Stays via Stay22

Stays near Ranch Lake

Compare lakeside cabins, hotels, and vacation rentals near Ranch Lake in Oconto County, Wisconsin — live availability and prices for your trip. Switch the map to Satellite to see the lake and how close each stay is to the water.

Top-rated places to stay near Ranch Lake

Prices for Oct 16–18, 4 adults. Change dates on the map below.

Availability and prices from Stay22 partners (Booking.com, Vrbo, Expedia). We may earn a commission from bookings, at no extra cost to you.

Planning a whole trip? See where to stay at Wisconsin’s top lakes →

Follow Ranch Lake’s readings

Email me when new measurements post for this lake. Updates stay free.

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Fish Species

Panfish Largemouth Bass Northern Pike

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

Fishing Ranch Lake

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 7 years of monitoring (2020–2026).

Water clarity
Improving
7 years
Phosphorus
Improving
-2.45 µg/L/yr3 years

See year-by-year chart →

Nearby Lakes in Oconto County

Halfmoon Lake17 ft clear—View →Pickerel Lake4.5 ft clear · Eutrophic—View →Bass Lake—View →Pickerel Lake—View →White Potato Lake6.5 ft clear · Mesotrophic—View →Shay Lake15 ft clear · Mesotrophic—View →

Frequently asked questions about Ranch Lake

Where is Ranch Lake?: Ranch Lake is a lake in Oconto County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Ranch Lake?: Ranch Lake in Oconto County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 12.5 ft visibility. Phosphorus: 14.4 µg/L. Maximum depth: 44 ft. Surface area: 52 acres.
Is Ranch Lake safe to swim in?: Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
What is the water temperature of Ranch Lake?: Ranch Lake typically sits around 78°F at the surface in July, from 9 EPA Water Quality Portal field readings (2024–2025). That is a typical value for the month, not a live reading.
How deep is Ranch Lake?: Ranch Lake has a maximum depth of 44 feet. The lake covers 52 acres.
What fish are in Ranch Lake?: Fish species found in Ranch Lake include Panfish, Largemouth Bass, Northern Pike. Ranch Lake is located in Oconto County, Wisconsin.
What did the DNR fisheries survey find at Ranch Lake?: Wisconsin DNR lists Panfish as present on Ranch Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Ranch Lake’s water-quality measurements separately, and the water-quality trend over 7 years of monitoring is improving. Catch rate is not a swim clearance and is not a weekly bite report.
Are there boat ramps on Ranch Lake?: Ranch Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Ranch Lake. Public access is listed as yes.
Can I fish at Ranch Lake?: Ranch Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Seasons, size and bag limits, and whether you need a license are set by Wisconsin's fish and wildlife agency, so check its current regulations before you go.

Explore Ranch Lake across LakeQuality

Wisconsin Fishing Guide

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Species activity outlook by water temperature and season

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Every Wisconsin lake with its Wisconsin DNR measurements

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Official ratings and named-lake measurements

State Parks Near Ranch Lake

Governor Thompson State Park

State Park · 11.4 mi

Copper Culture State Park

State Park · 24.5 mi

Other Lakes in Wisconsin

Gilas Lake

Marinette County · 15 ft

Thunder Lake

Marinette County · 18 ft

Little Newton Lake

Marinette County · 10.5 ft

Big Newton Lake

Marinette County · 17 ft

Lake Noquebay

Marinette County · 7.3 ft

Town Corner Lake

Marinette County · 9.7 ft

Mesotrophic Lakes in Wisconsin

High Falls Reservoir at Montana Lake Little Newton Lake Lake Noquebay

Where this data comes from

31 measurements from 1 monitoring station, 2020–2025. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

Wisconsin Department of Natural ResourcesWIDNR_WQX31 samples · 2020–2025

Analytical methods

Phosphorus by Colorimetry

Monitoring station identifiers (1)

WIDNR_WQX-433075

EPA condition classes from the National Lakes Assessment (EPA 841-R-24-006, Table 6-3), applied by ecoregion. See where the data comes from and data sources.