Lake Koshkonong

Jefferson, Dane, Rock County, Wisconsin

OverviewFacts & Figures

Physical Characteristics

Surface Area (Acres)10,595
Maximum Depth (ft)7
Mean Depth (ft)5
Shoreline (miles)
Bottom Composition10% sand, 10% gravel, 0% rock, 80% muck
Water Clarity — Secchi Depth (ft)
Trophic Status
Drainage BasinDRAINAGE
Lake Classlake
Public Access
Township
GPS Coordinates42.87240° N, 88.96120° W
WBIC (DNR ID)808700

Fish Species

7 species documented

AbundantCommonPresentRare
SpeciesAbundanceLast Survey
PanfishCommon
CatfishPresent
Largemouth BassPresent
MuskyPresent
Northern PikePresent
Smallmouth BassPresent
WalleyePresent

Boat Landings

4 landings

NameTypeRampTrailersFee
Boat Landing 1Public
Boat Landing 2Public
Boat Landing 3Public
Boat Landing 4Public

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
Zebra MusselConfirmed

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