LakeList
FavoritesStateWisconsin
Boulder Lake
Enhanced dataInteractive depth contours
Boulder LakeVilas 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 93% of the lake. Small gaps between recordings are smoothly connected; larger unrecorded areas follow the lake's depth model calibrated to the DNR-documented 23-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 Boulder Lake.
Start here
Fishing
Fishing at Boulder Lake
Fishery
Notable species
WalleyeMuskyPanfishLargemouth BassNorthern PikeSmallmouth Bass
Angler reports · Fishbrain
What anglers catch here
Anglers have logged 21 catches on Boulder Lake via Fishbrain — 6 in the last 30 days, most recently on Jul 16, 2026.
Most-reported species
- Smallmouth bass
- Yellow perch
13 of the 21 logged catches didn’t name a species and aren’t listed above.
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
Boulder Lake water temperature today
Modeled surface-temperature estimate built from seasonal climate, lake depth, and live National Weather Service air temperatures near this lake.
68°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.
DNR water check
Water quality quick take
Historical volunteer-monitoring record for this lake.
Last sampled Aug 2021Volunteer monitoring 1984–2021
DNR volunteers monitored this lake for about 37 years, ending in 2021. Its final monitored summers showed hazy water (~5.9 ft Secchi) in 2020, moderate algae (chlorophyll ~8 µg/L) in 2020, and moderate nutrients (phosphorus ~21 µg/L) in 1985. After 5 years without samples, these readings describe the lake as it was, not as it is.
| Year | Secchi | Chlorophyll-a | Total phosphorus |
|---|---|---|---|
| 2021 | 5.8 ft (1) | 8.0 µg/L (1) | — |
| 2020 | 5.9 ft (2) | 8.0 µg/L (2) | — |
| 2019 | 6.1 ft (2) | 6.0 µg/L (2) | — |
| 2018 | 5.8 ft (2) | 6.0 µg/L (3) | — |
| 2003 | 8.5 ft (1) | 7.0 µg/L (1) | — |
| 1990 | 7.0 ft (3) | — | — |
Boulder Lake - Deep HoleStation 643229
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 maps2 converted map sheetsFishing 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
Boulder Lake depth maps
2 converted map sheets. These historical surveys are not for navigation.
Navigable depth map
Boulder Lake · 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 2338300 · 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.
516surface acres
23max depth feet
2public access points
46.1247, -89.6609latitude, longitude
Access
Public access points
Boat launchBoat Ramp46.12380, -89.69067Managed by Wisconsin DNR
DNR verifiedDirections
Boat launchBoulder Lake Boat Ramp46.13226, -89.65611Managed by STATE(DNR)TOWN OF BOULDER JUNCTIONRamp surface: Concrete PanelsADA-accessible feature: YesVerified 2026-07-12
Nearby
Trip-planning places
No nearby trip-planning places yet
Depth FAQ
How deep is Boulder Lake?
Boulder Lake is 23 feet deep at its deepest point and averages about 12 feet, according to Wisconsin DNR records.
Is there a free depth map of Boulder Lake?
Yes. LakeList publishes a free interactive depth contour map of Boulder Lake 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 Boulder Lake 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 Pagesname, coordinates, county, source identifiers
LakeList record updated 2026-07-12
Keep exploring