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Fourmile Lake
Enhanced dataInteractive depth contours
Fourmile LakeOneida County, WI
Contours load with map
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 52% of the lake. Small gaps between recordings are smoothly connected; larger unrecorded areas follow the lake's depth model calibrated to the DNR-documented 29-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 Fourmile Lake.
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Fishing forecast
Best windows for Fourmile Lake
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
Fourmile Lake water temperature today
Modeled surface-temperature estimate built from seasonal climate, lake depth, and live National Weather Service air temperatures near this lake.
74°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
From Wisconsin DNR / Citizen Lake Monitoring readings at Fourmile Lake - Deep Hole.
Sampled Jun 2026Volunteer monitoring since 1993
Murky water — summer clarity of 2.9 ft ranks among the lowest of monitored Wisconsin lakes.
Based on July–August volunteer averages from 2022–2024; each value shows its own year.59Eutrophic5-yr summer TSI
Nutrient-rich, greener water — more algae and plant growth, common in shallower lakes.
Water claritySecchi disk depth
2.9 ftJul–Aug 2024 avg (3 readings)
MurkyStable since 2018
Clearer than 9% of 596 monitored Wisconsin lakes with current readings.
AlgaeChlorophyll-a
12.5 µg/LJul–Aug 2022 avg (2 readings)
ElevatedNo recent nutrient readings — last measured 2013.
All readings by year · station details · methodology
Summer averages (July/August)
July/August means; counts in parentheses show how many samples went into each average.
| Year | Secchi | Chlorophyll-a | Total phosphorus |
|---|---|---|---|
| 2025 | 3.0 ft (1) | — | — |
| 2024 | 2.9 ft (3) | — | — |
| 2023 | 3.8 ft (1) | — | — |
| 2022 | 3.5 ft (4) | 12.5 µg/L (2) | — |
| 2021 | 3.8 ft (3) | — | — |
| 2020 | 2.7 ft (3) | — | — |
| 2019 | 3.5 ft (4) | — | — |
| 2018 | 2.2 ft (6) | — | — |
| 2017 | 2.2 ft (3) | — | — |
| 2016 | 2.8 ft (2) | — | — |
Latest individual samples: Secchi 3 ft (2026-06-17), chlorophyll-a 12 µg/L (2022-10-20), and total phosphorus 23 µg/L (2013-02-14).
Secchi clarity is how deep a black-and-white disk stays visible from the surface — more feet means clearer water.
Chlorophyll-a is an algae pigment; higher values signal more algae in the water column.
Total phosphorus is a nutrient that feeds algae and aquatic plants. It is not a weed survey — depth, bottom type, water movement, and management change the actual lake experience.
Fourmile Lake - Deep HoleStation 443098 · TSI based on Secchi
Modeled from DNR/CLMN monitoring — not a safety or swim-condition report. Verify current conditions locally. 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
Fourmile Lake depth maps
1 converted map sheet. These historical surveys are not for navigation.
Navigable depth map
Fourmile 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 1610800 · 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.
210surface acres
29max depth feet
0public access points
45.8469, -89.0813latitude, longitude
Access
Public access points
No mapped access points yet
LakeList has not matched a public launch, park, or shoreline access point for this lake yet.
Nearby
Trip-planning places
No nearby trip-planning places yet
Fishery
Notable species
MuskyWalleyeLargemouth BassNorthern PikePanfishSmallmouth Bass
Depth FAQ
How deep is Fourmile Lake?
Fourmile Lake is 29 feet deep at its deepest point and averages about 12 feet, according to Wisconsin DNR records.
Is there a free depth map of Fourmile Lake?
Yes. LakeList publishes a free interactive depth contour map of Fourmile 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 Fourmile 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 Mapsname, coordinates, county, source identifiers
LakeList record updated 2026-07-14
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