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

How deep is Gilas Lake?

Gilas Lake has a maximum depth of 88 feet. The lake covers 135 acres.

What fish are in Gilas Lake?

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

Are there boat ramps on Gilas Lake?

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

Can I fish at Gilas Lake?

Gilas 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.

Gilas Lake

Marinette County, Wisconsin135 acresView map Directions

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

Clarity

15 ft

Clearer than most

Secchi · sampled 2026

Phosphorus

12.6 µg/L

Less phosphorus than most

Measured by Wisconsin DNR

Max depth

88 ft

Bathymetric survey

Area

135 acres

Surface area

Type

Oligotrophic

Trophic class

Trend

Improving

7 years of samples

Oligotrophic
Zebra Mussel
88 ft max depth
Public access

See the measurements Directions Where to stay

Gilas Lake in Marinette County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 15 ft visibility. Phosphorus: 12.6 µg/L. Maximum depth: 88 ft. Surface area: 135 acres.

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

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Gilas Lake is a 135-acre cold, clear oligotrophic lake in Marinette County, Wisconsin with a maximum depth of 88 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 9 other monitored lakes in Marinette County, Gilas Lake ranks #7 for water quality.

Source: EPA Water Quality Portal sampling records, Wisconsin DNR Surface Water, last sampled 2026-06-29. Methodology: how these readings are compared.

Gilas Lake covers about 140 acres in Marinette County. It has one public boat landing. For a place on the water, look through cabin and lake-house rentals near Gilas Lake on Vrbo. For a hotel or motel room, Booking.com and Expedia both search around the lake.

What Gilas Lake is good for

From access and monitoring records, not editorial picks.

Clear water15 ft of visibility
Boat launch1 documented ramp
Fishing3 species recorded
Deep water88 ft surveyed max depth

Swimming conditions

Readings only

Low algae

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 Gilas 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 →

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Water quality measurements for Gilas Lake

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

Crystal clear, you can see 15 ft down. Phosphorus 12.6 µg/L. TSI 39.

Water quality readings
Measure	Reading	Where it sits
Water clarity (Secchi depth)	15ft	Measured, not scored How deep a black-and-white disk stays visible from the surface. Higher is clearer.
Total phosphorus	12.6µg/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.	39	Oligotrophic OligotrophicMesotrophicEutrophicHypereutrophic

Low nutrients, clear water. No reading is a swimming clearance.

Ask about Gilas Lake

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

DNR fisheries survey

Wisconsin DNR lists Panfish as present on Gilas Lake.

A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Gilas 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 2002. 1 station on file (most recent sample 2025).

DNR Assessment

Excellent · Deep Seepage lake

Trophic State Index 33 (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 Gilas Lake covering fish populations, stocking, water quality, and management. 1 report on file.

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

2022
Gilas Lake comprehensive survey, 2022
Comprehensive Survey · WI DNR · 2022 (PDF)

Lake Details

Max depth

88 ft

Surface area

135 acres

Public access

Yes

Listed by Wisconsin DNR

Lake Size & Watershed

Watershed (drainage) area

2 sq mi

HydroLAKES / HydroSHEDS

Shoreline

2.2 mi

HydroLAKES / HydroSHEDS

Elevation

840 ft

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

Recreation & Access

Boat Landings

Yes

Public Access

Gilas 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 Gilas Lake

Compare lakeside cabins, hotels, and vacation rentals near Gilas Lake in Marinette 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 Gilas Lake

Prices for Oct 9–11, 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 Gilas 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 Gilas 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.

Chinese Mystery SnailZebra Mussel

Water Quality Trend: Improving

Based on 7 years of monitoring (2020–2026).

Water clarity
Improving
6 years
Phosphorus
Improving
-0.41 µg/L/yr7 years

See year-by-year chart →

Nearby Lakes in Marinette County

Little Nelligan Lake—View →Nelligan Lake—View →Giese Lake—View →Yankee Lake3 ft clear · Eutrophic—View →Grass Lake—View →Sandstone Flowage Lake5.5 ft clear—View →

Frequently asked questions about Gilas Lake

Where is Gilas Lake?: Gilas Lake is a lake in Marinette County, Wisconsin. Its water-quality measurements are published by Wisconsin DNR and shown on this page as reported.
What is the water quality of Gilas Lake?: Gilas Lake in Marinette County, Wisconsin has water-quality measurements published by Wisconsin DNR, shown here as reported. Water clarity: 15 ft visibility. Phosphorus: 12.6 µg/L. Maximum depth: 88 ft. Surface area: 135 acres.
Is Gilas Lake safe to swim in?: Nutrient and algae readings are not a swimming clearance. Check local advisories before you swim.
How deep is Gilas Lake?: Gilas Lake has a maximum depth of 88 feet. The lake covers 135 acres.
What fish are in Gilas Lake?: Fish species found in Gilas Lake include Panfish, Largemouth Bass, Northern Pike. Gilas Lake is located in Marinette County, Wisconsin.
What did the DNR fisheries survey find at Gilas Lake?: Wisconsin DNR lists Panfish as present on Gilas Lake. A DNR fisheries survey reports fish abundance and catch rates, not water quality. LakeQuality shows Gilas 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 Gilas Lake?: Gilas Lake has 1 documented boat landing in the USGS National Boat Ramps inventory. Named access points include Gilas Lake. Public access is listed as yes.
Can I fish at Gilas Lake?: Gilas 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 Gilas Lake across LakeQuality

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Species activity outlook by water temperature and season

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Official ratings and named-lake measurements

State Parks Near Gilas Lake

Governor Thompson State Park

State Park · 12.5 mi

Copper Culture State Park

State Park · 23.1 mi

Other Lakes in Wisconsin

Ranch Lake

Oconto County · 12.5 ft

White Potato Lake

Oconto County · 6.5 ft

Shay Lake

Oconto County · 15 ft

Round Lake

Oconto County · 16.8 ft

Kelly Lake

Oconto County · 10.5 ft

Boundary Lake

Oconto County · 14 ft

Oligotrophic Lakes in Wisconsin

Halfmoon Lake Bass Lake Round Lake Long Lake

Where this data comes from

40 measurements from 2 monitoring stations, 2020–2026. Retrieved from the EPA Water Quality Portal on 2026-08-02.

Collected and reported by

Wisconsin Department of Natural ResourcesWIDNR_WQX40 samples · 2020–2026

Analytical methods

Phosphorus by Colorimetry

Monitoring station identifiers (2)

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.

Other records on this page

Lake size & watershed from HydroLAKES (HydroSHEDS)

Fish and recreation data from Wisconsin DNR Lakes

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