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Lake Onalaska
Enhanced dataInteractive depth contours
Lake OnalaskaLa Crosse 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 53% of the lake. Small gaps between recordings are smoothly connected; larger unrecorded areas follow the lake's depth model calibrated to the DNR-documented 40-ft maximum depth. More accurate than a pure model, but still an estimate. Not for navigation.LakeList assistant
Plan your lake day
Fishing spots, food, lodging, marinas, and rentals around Lake Onalaska.
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Fishing forecast
Best windows for Lake Onalaska
Weather-based planning built from the National Weather Service hourly forecast near this lake.
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Checking wind, precipitation, and near-term weather windows.
Water temperature
Lake Onalaska water temperature today
Modeled surface-temperature estimate built from seasonal climate, lake depth, and live National Weather Service air temperatures near this lake.
76°FPeak summer
Seasonal estimate. Checking current National Weather Service air temperatures…
Warmest water of the year. Fish hold deeper or feed in low light; swimming and watersports are at their best.
Estimates are modeled, not measured. Actual temperatures vary with depth, wind mixing, and recent weather — verify conditions before swimming, boating, or heading onto ice.
DNR water check
Water quality quick take
Historical volunteer-monitoring record for this lake.
Last sampled Aug 2010Volunteer monitoring 2005–2010
DNR volunteers monitored this lake for about 5 years, ending in 2010. In 2010 the water showed murky water (~1.8 ft Secchi), elevated algae (chlorophyll ~13 µg/L), and high nutrients (phosphorus ~598 µg/L). After 16 years without samples, these readings describe the lake as it was, not as it is.
| Year | Secchi | Chlorophyll-a | Total phosphorus |
|---|---|---|---|
| 2010 | 1.8 ft (1) | 13.0 µg/L (1) | 598.0 µg/L (1) |
| 2008 | — | 6.0 µg/L (1) | 88.0 µg/L (1) |
| 2007 | — | 23.0 µg/L (1) | 54.0 µg/L (1) |
| 2006 | — | 7.0 µg/L (1) | 43.0 µg/L (1) |
| 2005 | — | 12.0 µg/L (1) | 56.0 µg/L (1) |
Lake Onalaska - Brice Prairie Channel 1/4 Mile Above LakeStation 323132
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 Onalaska depth maps
1 converted map sheet. These historical surveys are not for navigation.
Navigable depth map
Lake Onalaska · 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 728100 · 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.
8,391surface acres
40max depth feet
7public access points
43.9067, -91.2971latitude, longitude
Access
Public access points
Boat launchBrice Prairie Channel Landing (Fred Funk)43.93131, -91.30866Managed by Wisconsin DNR
DNR verifiedDirections
Boat launchBrice Prairie Walk-In Access43.93713, -91.31667Managed by Wisconsin DNR
DNR verifiedDirections
Boat launchFishermans Road43.88542, -91.24546Managed by Wisconsin DNR
DNR verifiedDirections
Boat launchFishermans Road43.88750, -91.25519Managed by Wisconsin DNR
DNR verifiedDirections
Boat launchNelson Park Landing43.89523, -91.26893Managed by Wisconsin DNR
DNR verifiedDirections
Boat launchRamp43.91450, -91.26558Managed by Wisconsin DNR
DNR verifiedDirections
Boat launchUpper French Island Spillway Landing43.86918, -91.27541Managed by Wisconsin DNR
DNR verifiedDirections
Nearby
Trip-planning places
No nearby trip-planning places yet
Fishery
Notable species
PanfishLargemouth BassNorthern PikeSmallmouth BassWalleye
Depth FAQ
How deep is Lake Onalaska?
Lake Onalaska is 40 feet deep at its deepest point and averages about 6 feet, according to Wisconsin DNR records.
Is there a free depth map of Lake Onalaska?
Yes. LakeList publishes a free interactive depth contour map of Lake Onalaska 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 Onalaska 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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