Big Bay Town Park: Lake Superior Agate & Jasper Rockhounding in Ashland County, Wisconsin
Updated July 2026
Big Bay Town Park on Madeline Island gives collectors a Lake Superior beach reachable by the Bayfield ferry. The long pebble and sand beach along Big Bay yields Lake Superior agates, jasper, and basalt cobbles, some carrying zeolite and thomsonite amygdules. The town park is public and open to collecting, in contrast to the adjacent Big Bay State Park, where rock removal requires written state permission. Reported finds include lake superior agate, jasper, thomsonite, basalt. Below: coordinates, access notes, nearby spots, and trip-planning links.
Big Bay Town Park photos
Public image records connected to this spot or its reported material.
Map showing Big Bay Town Park in Ashland County, Wisconsin
Quick details
- Access
- Public area
- County
- Ashland County
- State
- Wisconsin
- Nearest road
- Hagen Road
- Postcode
- 54850
- Coordinates
- 46.78460, -90.64780
Geology at Big Bay Town Park
This spot sits on ground mapped as water. Tough silica like agate and jasper typically survives weathering and collects as float in drainages and gravel.
- Mapped unit
- water
- Elevation
- 590 ft
Geologic mapping via Macrostrat and the underlying state geological survey maps (CC BY 4.0). Bedrock at the surface can vary within a mapped unit.
Best time to visit Big Bay Town Park
Best months: April to October. Typical highs run 77°F in midsummer and 22°F in midwinter, with winter lows near 7°F.
Climate normals: NOAA 1991-2020 monthlies, MADELINE IS station (6 mi away).
Land & collecting status
Generally open to casual rockhounding
Most public-tagged spots sit on BLM, U.S. Forest Service, or other federal land where reasonable hand collecting of common rocks and minerals is allowed. Confirm posted rules and active mining claims before you dig.
Public-land rules vary by agency, season, and field office. The RockHoundR app pulls live BLM, USFS, NPS, and tribal overlays so you can see exactly which agency manages the ground at this spot.
Sources & verification
Spot details combine the public RockHoundR location dataset, normalized mineral labels, agency land-status checks in the app, and community submissions. Coordinates are approximate until verified in the field.
Sources: RockHoundR public spot dataset, app land overlays, and local agency review before each trip.
Found at Big Bay Town Park
Each chip opens all spots that produce that material; the encyclopedia link opens the full ID and field guide.
Nearby rockhounding spots
Other rockhounding spots within driving distance of Big Bay Town Park.
- Saxon Harbor County ParkTop pick in WisconsinIron County, Wisconsin · 18 mi awayLake Superior Agate, Jasper, Copper
- Near Saxon FallsTop pick in WisconsinIron County, Wisconsin · 21 mi awayCalcite, Chlorite, Epidote
- General AreaAshland County, Wisconsin · 25 mi awayCopper
- Iron CountyIron County, Wisconsin · 29 mi awayAgate, Jasper
- Montreal MineIron County, Wisconsin · 32 mi awayActinolite, Barite, Selenite
- Iron CountyIron County, Wisconsin · 32 mi awayCopper
- Ashland CountyAshland County, Wisconsin · 37 mi awayAgate, Jasper
- Bayfield CountyTop pick in WisconsinBayfield County, Wisconsin · 40 mi awayAgate, Jasper
Across the state line from Big Bay Town Park
Big Bay Town Park is close enough to the Wisconsin border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.
- Little Girls Point County ParkGogebic County, Michigan · 20 mi awayBasalt, Granite, Unakite
- Black River HarborGogebic County, Michigan · 30 mi away
- Gull RockLake County, Minnesota · 45 mi awayLake Superior Agate
- Beaver BayTop pick in MinnesotaLake County, Minnesota · 45 mi awayLake Superior Agate, Thomsonite
- Union Bay CampgroundOntonagon County, Michigan · 48 mi away
- Little Marais RiverLake County, Minnesota · 48 mi awayThomsonite, Zeolite
Big Bay Town Park FAQ
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More rockhounding in Wisconsin
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