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Lake Koshkonong
Enhanced dataInteractive depth contours
Lake KoshkonongJefferson County, WI
Contours load with map Access
Interactive depth contours5-foot typical interval · Sonar-derived depth (C-MAP Genesis) · Gaps interpolated · Not for navigation
Source: C-MAP Genesis community sonar (derived)high confidence · QA passed · Select a contour to inspect its mapped depthDepths decoded from C-MAP Genesis Social Map community sonar recordings (used with permission), covering 11% of the lake. Small gaps between recordings are smoothly connected; larger unrecorded areas follow the lake's depth model calibrated to the DNR-documented 7-ft maximum depth. More accurate than a pure model, but still an estimate. Not for navigation.LakeList assistant
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Fishing spots, food, lodging, marinas, and rentals around Lake Koshkonong.
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Fishing
Fishing at Lake Koshkonong
Fishery
Notable species
PanfishCatfishLargemouth BassMuskyNorthern PikeSmallmouth BassWalleye
Angler reports · Fishbrain
What anglers catch here
Anglers have logged 393 catches on Lake Koshkonong via Fishbrain — none in the last 30 days.
Latest reported catch: May 29, 2026
Most-reported species
- Largemouth bass
- Northern pike
- Walleye
- Channel catfish
- Freshwater drum
- White bass
Show 8 more species
- Bowfin reported as “Eyetail bowfin”
- Black crappie
- Bluegill
- Yellow perch
- Common carp
- Muskellunge
- Smallmouth bass
- Sauger
35 of the 393 logged catches didn’t name a species and aren’t listed above.
Seasonality
All fishOf the 393 logged catches, 307 carry a month and 293 carry a year; the charts cover those.
2021 had the most reports (116).
Counts reflect reporting activity, not fish populations. Waterbody location is provider-level; exact spots and angler details aren’t shown.
Fishery details for this lakeExplore this area on FishbrainNWS weather
Weather windows
Weather-based planning from the National Weather Service hourly forecast near this lake — not a catch forecast.
Loading latest forecast…
Checking wind, precipitation, and near-term weather windows.
Water temperature
Lake Koshkonong water temperature today
Modeled surface-temperature estimate built from seasonal climate, lake depth, and live National Weather Service air temperatures near this lake.
72°FWarm
Seasonal estimate. Checking current National Weather Service air temperatures…
Comfortable summer pattern. Bass and panfish are active; early and late hours beat the midday heat.
Estimates are modeled, not measured. Actual temperatures vary with depth, wind mixing, and recent weather — verify conditions before swimming, boating, or heading onto ice.
Wisconsin DNR water assessment
Impaired waterbody listed
The DNR lists this waterbody as impaired. This notice is not itself a closure; review the official assessment and current guidance before your trip.
303(d) / impairment recordRecreation restrictions noted
Low DO, Degraded Habitat, Excess Algal Growth, Turbidity, EutrophicationPollutants: Total Phosphorus, Sediment/Total Suspended Solids
- Status
- TMDL Approved
- Public health
- General Advice
- Recreation
- Recreational Restrictions
- Aquatic life
- Not specified
Water is impaired due to one or more pollutants and associated quality impacts.
Review DNR water quality Check consumption advice Source updated 2026-03-25 · LakeList verified 2026-07-12
DNR water check
Water quality quick take
Historical volunteer-monitoring record for this lake.
Last sampled date unknown
Individual readings are not retained for this lake — the index below is what the monitoring record summarizes.
77 five-year summer trophic state index · Hypereutrophic. Very nutrient-rich water — heavy algae and plant growth pressure.
Listed as impaired on the DNR/EPA water-condition assessment — see the notice on this page for details.Lake Koshkonong - N of Charley Bluff landingStation 10022780 · TSI based on chlorophyll
Historical record only — no current water-quality data exists for this lake. LakeList verified 2026-07-12.Official Wisconsin information
Plan with DNR sources
LakeList links to the authoritative record so you can verify maps, rules, and current notices before leaving.
Historical DNR depth maps1 converted map sheetView DNR depth mapHistorical map · not for navigationFishing regulationsVerify current seasons, limits, and restrictionsOfficial DNR lake pageFacts, advisories, boating, and water qualityWater quality reportsMonitoring stations, clarity, and DNR reportsInvasive speciesVerified, observed, and historical AIS recordsBoating ordinancesLocal slow-no-wake and water-use restrictionsFish consumption advisoriesStatewide and waterbody-specific health guidance
Historical depth maps are not for navigation. Verify regulations and access at the official source before your trip.
Historical Wisconsin DNR maps
Lake Koshkonong depth maps
1 converted map sheet. These historical surveys are not for navigation.
Navigable depth map
Lake Koshkonong · sheet 1
Pan, zoom, and inspect the converted Wisconsin DNR historical map image in the browser. Historical survey — not for navigation.
Source: Wisconsin DNR · WBIC 808700 · image navigation only; spatial alignment pending · Historical lake maps are not for navigation.
Source: Wisconsin Department of Natural Resources. Converted for browser access with source URLs, checksums, and retrieval dates retained. Historical lake maps are not for navigation.
10,595surface acres
7max depth feet
4public access points
42.8714, -88.9652latitude, longitude
Access
Public access points
Boat launchAccess42.89781, -88.96002Managed by Wisconsin DNR
DNR verifiedDirections
Boat launchAccess at End Of Bingham Rd42.87300, -89.01311Managed by Wisconsin DNR
DNR verifiedDirections
Boat launchAccess at Wildlife Area - Vinnie Haha Rd42.88323, -88.90588Managed by Wisconsin DNR
DNR verifiedDirections
Boat launchAccess Nr N Charley Bluff Rd42.84317, -88.97408Managed by Wisconsin DNR
DNR verifiedDirections
Nearby
Trip-planning places
No nearby trip-planning places yet
Depth FAQ
How deep is Lake Koshkonong?
Lake Koshkonong is 7 feet deep at its deepest point and averages about 5 feet, according to Wisconsin DNR records.
Is there a free depth map of Lake Koshkonong?
Yes. LakeList publishes a free interactive depth contour map of Lake Koshkonong at a typical 5-foot interval, with an optional 3D underwater view, derived from C-MAP Genesis community sonar (derived) survey data.
Where does the Lake Koshkonong depth map come from?
The interactive depth contours are derived from C-MAP Genesis community sonar (derived). Each contour set passes a visual QA review against the source document before it is published. The depths are derived from community sonar recordings (C-MAP Genesis Social Map, used with permission), with gaps between recordings interpolated; not for navigation.
Trust and freshness
Where this lake data comes from
Wisconsin DNR Lake Mapsname, coordinates, county, source identifiers
LakeList record updated 2026-07-14
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