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Granite Lake
Enhanced dataInteractive depth contours
Granite LakeBarron 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 80% of the lake. Small gaps between recordings are smoothly connected; larger unrecorded areas follow the lake's depth model calibrated to the DNR-documented 34-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 Granite Lake.
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Fishing forecast
Best windows for Granite 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
Granite 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.
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
Excess Algal GrowthPollutants: Unknown Pollutant
- Status
- 303d Listed
- 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
From Wisconsin DNR / Citizen Lake Monitoring readings at Granite Lake at Deep Hole.
Sampled May 2026Volunteer monitoring since 1994
Somewhat hazy water — summer clarity of 8 ft is lower than most monitored Wisconsin lakes.
Based on July–August volunteer averages from 2022–2025; each value shows its own year.57Eutrophic5-yr summer TSI
Nutrient-rich, greener water — more algae and plant growth, common in shallower lakes.
Water claritySecchi disk depth
8 ftJul–Aug 2022 avg (2 readings)
Slight hazeStable since 2017
Clearer than 27% of 596 monitored Wisconsin lakes with current readings.
AlgaeChlorophyll-a
13.7 µg/LJul–Aug 2025 avg (3 readings)
ElevatedWorsening — up ~1015% vs earlier years
NutrientsTotal phosphorus — fuels plant & algae growth
24 µg/LLatest single sample · 2025-07-08
Moderate2021–2025
Moderate phosphorus can support noticeable plant/algae growth.
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 | 5.5 ft (1) | 13.7 µg/L (3) | 24.0 µg/L (1) |
| 2024 | 5.0 ft (1) | 289.0 µg/L (1) | 24.0 µg/L (1) |
| 2023 | — | 9.5 µg/L (2) | 17.0 µg/L (1) |
| 2022 | 8.0 ft (2) | 6.0 µg/L (2) | — |
| 2021 | 7.0 ft (2) | 12.0 µg/L (2) | 21.0 µg/L (1) |
| 2020 | 7.0 ft (3) | 10.0 µg/L (2) | — |
| 2019 | 5.8 ft (2) | 10.5 µg/L (2) | — |
| 2018 | 7.8 ft (2) | 15.0 µg/L (1) | — |
| 2017 | 6.1 ft (2) | — | — |
| 2016 | 6.3 ft (2) | 8.5 µg/L (2) | — |
Latest individual samples: Secchi 5.5 ft (2025-07-08), chlorophyll-a 4 µg/L (2026-05-31), and total phosphorus 24 µg/L (2025-07-08).
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.
Granite Lake at Deep HoleStation 033177 · TSI based on chlorophyll
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
Granite Lake depth maps
1 converted map sheet. These historical surveys are not for navigation.
Navigable depth map
Granite 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 2100800 · 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.
Wisconsin DNR fisheries survey
Fish population survey
Structured LakeList extraction from the 2020 DNR fisheries survey. Population estimates, density, and catch-rate indices use different units, methods, and scopes, so each value is presented in its original form rather than normalized against a different measure.
Survey indicatorsValues keep their source unit and method; unlike measures are not scaled or compared.
Management contextGranite Lake (WBIC 2100800) only; fish metrics retain 2019 gear/year and creel metrics retain 2019-2020 angler-estimate scope.
Human-reviewed 2019 fish-population observations and 2019-2020 angler creel estimates for Granite Lake.
- Historical survey snapshot; not current regulations or navigation guidance.
- Creel values describe anglers and projected catch/harvest, not fish-population abundance.
- The report's 17.7% largemouth-bass mortality narrative conflicts with its plotted A=0.34 and was excluded.
- Only current-survey values were promoted; historical and comparison-lake values were excluded.
All species
3,759 angler-hours2019-2020 total angler effort · p. 1624.4 angler-hours/acre2019-2020 total angler effort per acre · p. 162,931 angler-hours2019 open-water angler effort · p. 1619 angler-hours/acre2019 open-water angler effort per acre · p. 16
Black Crappie
22 fish2019 electrofishing catch · p. 156.3 fish/mile2019 electrofishing catch rate · p. 156 fish/mile2019 catch rate for fish at least 8 inches · p. 157.2 inches2019 minimum length · p. 15
Bluegill
61 fish2019 electrofishing catch · p. 1417.4 fish/mile2019 electrofishing catch rate · p. 1416.3 fish/mile2019 catch rate for fish at least 6 inches · p. 142.9 fish/mile2019 catch rate for fish at least 8 inches · p. 14
Largemouth Bass
25 fish2019 electrofishing catch · p. 117.1 fish/mile2019 electrofishing catch rate · p. 114.6 fish/mile2019 catch rate for fish at least 14 inches · p. 1112.6 inches2019 minimum length · p. 11
Northern Pike
169 angler-hoursDirected angler effort · p. 181.1 angler-hours/acreDirected angler effort per acre · p. 183.6 percentShare of recreational fishery · p. 18491 fishProjected angler catch · p. 18
Walleye
1,236 adult fish2019 adult population estimate · p. 71,004 adult fish2019 population estimate lower 95% confidence limit · p. 71,469 adult fish2019 population estimate upper 95% confidence limit · p. 78 adult fish/acre2019 adult population density · p. 7
Granite Lake fishery survey report, 2019-2020Matched by exact wbic name county · WBICs 2100800 · verified 2026-07-20Wisconsin DNR fisheries report; LakeList operator documented permission to leverage this public report with source attribution.
155surface acres
34max depth feet
1public access points
45.5775, -92.0069latitude, longitude
Access
Public access points
Boat launchAccess45.57826, -92.00914Managed by Wisconsin DNR
DNR verifiedDirections
Nearby
Trip-planning places
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Fishery
Notable species
Largemouth BassNorthern PikePanfishWalleye
Depth FAQ
How deep is Granite Lake?
Granite Lake is 34 feet deep at its deepest point and averages about 18 feet, according to Wisconsin DNR records.
Is there a free depth map of Granite Lake?
Yes. LakeList publishes a free interactive depth contour map of Granite 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 Granite 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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