Lake Onalaska

La Crosse County, Wisconsin

OverviewFacts & Figures

Physical Characteristics

Surface Area (Acres)8,391
Maximum Depth (ft)40
Mean Depth (ft)6
Shoreline (miles)
Bottom Composition
Water Clarity — Secchi Depth (ft)
Trophic Status
Drainage BasinDRAINAGE
Lake Classlake
Public Access
Township
GPS Coordinates43.90500° N, 91.29930° W
WBIC (DNR ID)728100

Fish Species

5 species documented

AbundantCommonPresentRare
SpeciesAbundanceLast Survey
PanfishAbundant
Largemouth BassCommon
Northern PikeCommon
Smallmouth BassPresent
WalleyePresent

Boat Landings

7 landings

NameTypeRampTrailersFee
Boat Landing 1Public
Boat Landing 2Public
Boat Landing 3Public
Boat Landing 4Public
Boat Landing 5Public
Boat Landing 6Public
Boat Landing 7Public

Invasive Species

Invasive species have been documented in or near this lake. Please clean, drain, and dry all watercraft and equipment before leaving to prevent spread.

SpeciesStatusFirst Detected
Curly-Leaf PondweedConfirmed
Eurasian Water-MilfoilConfirmed
Faucet SnailConfirmed
Hybrid Eurasian / Northern Water-MilfoilConfirmed
Purple LoosestrifeConfirmed
Water HyacinthConfirmed
Yellow IrisConfirmed

Data sourced from Wisconsin DNR lake surveys. Last scraped: 3/24/2026.