Big Brook Park: Fossil Hunting in Monmouth County, New Jersey
Updated July 2026
Big Brook is New Jersey's best known free fossil stream, cutting Late Cretaceous marine beds of the Navesink Formation that are roughly 70 million years old. Collectors regularly find shark teeth (Squalicorax and Cretolamna), belemnite guards of Belemnitella americana, and Exogyra oyster shells weathering out of the streambed. Monmouth County manages it as public parkland with published fossil-collecting rules, which is rare for an East Coast site. Reported finds include shark teeth, belemnite, fossils. Below: coordinates, access notes, nearby spots, and trip-planning links.
Big Brook Park photos
Public image records connected to this spot or its reported material.
Map showing Big Brook Park in Monmouth County, New Jersey
Quick details
- Access
- Public area
- County
- Monmouth County
- State
- New Jersey
- Nearest road
- Boundary Road
- Postcode
- 07746
- Coordinates
- 40.30600, -74.25600
Geology at Big Brook Park
This spot sits on Navesink Formation, mapped as sand that formed roughly 72 to 66 million years ago. Reworked sediments like these can carry fossils eroded from older beds upstream, typically as rolled bone fragments, teeth, and shell material.
- Mapped unit
- Navesink Formation
- Age
- 72–66 Ma (Late Cretaceous)
- Rock types
- sand
- Elevation
- 180 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 Brook Park
Best months: March to December. Typical highs run 87°F in midsummer and 42°F in midwinter, with winter lows near 23°F.
Climate normals: NOAA 1991-2020 monthlies, FREEHOLD-MARLBORO station (1 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 Brook 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 Brook Park.
- Ramanessin BrookTop pick in New JerseyMonmouth County, New Jersey · 6 mi awayShark Teeth, Fossils
- Poricy Park Fossil BedsTop pick in New JerseyMonmouth County, New Jersey · 9 mi awayBelemnite, Shark Teeth, Fossils
- SayrevilleMiddlesex County, New Jersey · 10 mi awayMarcasite, Pyrite, Petrified Wood
- Shark RiverTop pick in New JerseyMonmouth County, New Jersey · 12 mi awayShark Teeth, Fossils
- Long BranchMonmouth County, New Jersey · 15 mi awayQuartz
- ManasquanMonmouth County, New Jersey · 18 mi awayQuartz, Fossils, Petrified Wood
- KingstonSomerset County, New Jersey · 20 mi awayAgate, Prehnite, Quartz
- Rock Hill QuarrySomerset County, New Jersey · 20 mi awayAlbite, Chalcocite, Chrysocolla
Across the state line from Big Brook Park
Big Brook Park is close enough to the New Jersey border that the next-closest rockhounding spots are in a neighboring state. Worth knowing if you are already on the road.
- MorrisvilleBucks County, Pennsylvania · 28 mi awayJasper
- NewtownBucks County, Pennsylvania · 38 mi awayJasper, Petrified Wood
- FeastervilleBucks County, Pennsylvania · 38 mi awaySunstone, Agate, Feldspar
- Maple GlenBucks County, Pennsylvania · 45 mi awayPetrified Wood
- Bucks CountyBucks County, Pennsylvania · 45 mi awayPetrified Wood
- EurekaBucks County, Pennsylvania · 49 mi awaySmoky Quartz
Big Brook Park FAQ
Where is Big Brook Park?+
What rocks and minerals can you find at Big Brook Park?+
Is collecting allowed at Big Brook Park?+
What tools should I bring to Big Brook Park?+
When is the best time to visit Big Brook Park?+
How do I get to Big Brook Park?+
More rockhounding in New Jersey
See all 72 New Jersey spots →Open Big Brook Park on the map
Use the RockHoundR app for live land overlays, weather, geology, directions, and saved finds.
