Fossil Hunting at Big Brook Preserve, New Jersey
ALLOWED
No permit required
Key Conditions
- No permit or fee for individuals. Monmouth County caps groups at 10 without a Naturalist-led program, and Colts Neck requires a $25 permit for groups of 15–29 and $50 for 30 or more.
- Collect only in the stream itself. Both codes ban digging into or extracting fossils from the banks above the waterline.
- Limits differ by jurisdiction: Monmouth County allows what fits in a 12-oz can or sandwich bag per person per day, while Colts Neck caps harvest at five fossils per person per day, with a 6-inch trowel and an 18-inch screen
- Colts Neck's Hillsdale Road entrance has been closed by police order 'until further notice' since August 2025; use the county's Boundary Road lot in Marlboro
- Archaeological items and modern valuables found in the county park must be turned over to Park System staff within 48 hours
The Colts Neck entrance is closed; most guides haven't caught up
Nearly every Big Brook trip guide sends you to the Hillsdale Road entrance in Colts Neck. On August 26, 2025, Colts Neck Township posted a public notice that, by order of the township police and "to ensure public safety," the Hillsdale Road entrance to Big Brook Preserve is closed until further notice. The notice was last edited March 5, 2026, and was still posted when we checked on September 17, 2026. The legal way in right now is Monmouth County's Boundary Road lot at Big Brook Park in Marlboro, where the county's fossil rules apply.
One Creek, Two Rulebooks
| Rule | Big Brook Park (Monmouth County, Marlboro) | Big Brook Preserve (Colts Neck Township) |
|---|---|---|
| Legal source | Park System Supplemental Fossil Rules | Colts Neck Code §§ 177-43 to 177-48 + 2019 policy |
| Permit for small groups | None for 10 or fewer | None for fewer than 15 |
| Larger groups | Naturalist-led program required (>10) | $25 permit (15–29) / $50 (30+) |
| Daily take limit | 12-oz can or sandwich bag per person | 5 fossils per person |
| Digging tool | Hand tools ≤ 14 in. long; ≤ 6 in. deep | Trowel blade ≤ 6 in. |
| Screen | No mechanical sifters; no size set | ≤ 18 in. square |
| Where you may collect | Streambed; no digging into banks | Within the stream waterline only |
| Access in 2026 | Open: Boundary Road lot | Hillsdale Road entrance closed |
Compiled September 17, 2026 from the Monmouth County Park System's Supplemental Rules, Colts Neck Code Chapter 177 Article VII, Colts Neck's 2019 Rules and Policies, and the township's closure notice.
Big Brook's rules are unusual because the stream is regulated twice. Monmouth County manages Big Brook Park on the Marlboro side under its own supplemental rules. Colts Neck Township manages Big Brook Preserve under a municipal ordinance whose preamble says fossils "have been taken from the park in large quantities." Colts Neck's § 177-45 also declares that all fossils in the park belong to the township, the county and the State of New Jersey, which is why the ordinance treats collecting as a limited privilege rather than a right.
The numbers don't line up. A sandwich bag holds dozens of small shark teeth and belemnite fragments, all legal on the county side and many times the five-fossil Colts Neck limit. The stream doesn't come with boundary markers. So if you've walked a long way upstream or down, collect as if the stricter township rule applies.
The fossils themselves weather out of Late Cretaceous marine sands laid down roughly 70 to 66 million years ago, mostly the Navesink Formation, with Mount Laurel and Wenonah beds lower in the section. Each high-water event cuts the banks, drops fresh material onto the gravel bars, and sorts it by weight. That's why the rule against touching the banks costs collectors nothing: the stream does the digging for you.
If You Find Something That Isn't a Fossil
- 1
Recognize what triggers the rule
County Rule 9 covers 'archaeological items of historic significance' (for example, Native American points or colonial-era artifacts) and 'modern items of value' such as a ring, phone or wallet washed into the brook. Shark teeth and shells don't count.
- 2
Don't keep digging
Note where you found the item. The bank-digging and 6-inch depth limits still apply, even if you think there's more of it.
- 3
Contact the Park System within 48 hours
Call the Big Brook Park Ranger office or the Park Superintendent's office at 732-842-4000, ext. 4382. For ranger assistance at the park, call 732-577-8700.
- 4
Hand it over
Rule 9 requires the item to be turned over to Park System staff within 48 hours of the find.
- 5
Share notable fossils too
It's voluntary, but the county encourages sharing fossil finds with its naturalists at the Manasquan Reservoir Environmental Center, 732-751-9453.
When to Hunt Big Brook
Spring (Mar–May)
GoodSnowmelt and spring storms cut the banks and restock the gravel bars. Wait a day or two after heavy rain, because county Rule 12 warns that stream conditions 'can change rapidly especially from rainfall.' The park opens at 7 a.m.
Summer (Jun–Aug)
FairLow, warm water makes it the easiest season for kids, and the park stays open until 8 p.m. But weekend crowds pick the bars over, and the fresh supply depends on summer thunderstorms.
Fall (Sep–Nov)
GoodFewer people, and fallen leaves haven't yet hidden the gravel. Closing time drops to 7:30 p.m. on October 5 and 5:30 p.m. on November 1, so plan to leave earlier.
Winter (Dec–Feb)
PoorCold water and a 5:30 p.m. closing time. Bars scoured by winter storms can be excellent on a thaw day, but numb hands and swift, cold water make it a short, careful outing at best.
Before You Go
- Navigate to the Boundary Road lot in Marlboro, not Hillsdale Road, which has been closed since August 2025
- Check rainfall for the past 48 hours. High, muddy water is both unsafe and unproductive.
- Pack a screen no larger than 18 inches square and a trowel with a blade no longer than 6 inches
- Bring one sandwich-size zip bag per person. That's the county's daily limit.
- Count your group: more than 10 people needs a county Naturalist-led program
- Wear boots, since sharp objects in the streambed make footwear a posted requirement
Why the Colts Neck limit counts fossils, not weight
Most fossil limits on this site are written by weight, such as 25 pounds a day on BLM land. Big Brook's township rule is written by count, five fossils per person per day, because the problem Colts Neck described in § 177-43 was bulk removal of small teeth, not heavy specimens. For a family that screens for an afternoon, the practical effect is to keep your five best finds and put the rest back. The county's container limit works the other way: it doesn't care how many pieces you keep, only how much room they take up.
Getting to the Stream
Hours and access confirmed September 17, 2026 on the Monmouth County Park System's Big Brook Park page and the Colts Neck Township notice.
Permits & Licenses
| Permit | Required? | Notes |
|---|---|---|
| Individual or small-group fossil collecting | No | Monmouth County Supplemental Rule 1: 'There is no permit or fee required for individuals or for groups of 10 or fewer.' Colts Neck's 2019 Rules and Policies: 'Visiting with less than 15 people? NO PERMIT IS REQUIRED.' |
| Colts Neck group fossil-collecting permit | Yes | Email cnrecpks@coltsneck.org with the date, group size and a contact phone number, then mail a check payable to the Colts Neck Department of Recreation and Parks, 14 Heyers Mill Road, Colts Neck, NJ 07722. Permits are issued per day and valid from 8 a.m. to dusk under the 2019 policy (the ordinance text says 6 a.m.). The person in charge has to carry the permit. Group buses may use only the Hillsdale Road lot, which is currently closed. |
| Monmouth County groups larger than 10 | Yes | County Supplemental Rule 11 limits groups to 10 people. Larger groups must register for a Naturalist-led program through the Monmouth County Park System rather than applying for a permit. |
Time & Seasonal Restrictions
- Stream only: Colts Neck § 177-46(A)(5) limits collecting to fossils 'found within the actual stream waterline' and bans extraction from the streambed walls above it. County Rule 3 bans digging into the stream bank.
- Tools in the county park: hand tools no longer than 14 inches, with the streambed disturbed no deeper than 6 inches (Rule 5). No mechanical digging, drilling or sifting equipment (Rule 4).
- Tools in the Colts Neck preserve: trowels with a blade no longer than 6 inches, and screens no larger than 18 inches square (§ 177-46(A)(6))
- Quantity: in the county park, whatever fits in a 12-oz can or sandwich-size zip bag per person per day (Rule 8). In the Colts Neck preserve, no more than five fossils per person per day (§ 177-46(A)(7)).
- No damming or diverting the stream (Rule 7), and no disturbing vegetation or wildlife (Rule 6)
- Children under 14 must be accompanied by a parent or guardian who stays in visual contact at all times (Rule 10)
- Big Brook Park hours: opens at 7 a.m. and closes on a seasonal schedule (8 p.m. through Oct. 4, 7:30 p.m. Oct. 5–31, 5:30 p.m. from Nov. 1). Collecting is allowed only during posted hours (Rule 1).
- Colts Neck's Hillsdale Road entrance to Big Brook Preserve has been closed by order of the Colts Neck Township Police 'until further notice' since the notice posted August 26, 2025 (last edited March 5, 2026)
Equipment Notes
- A 1/4-inch or 1/8-inch mesh screen, no larger than 18 inches square. That size meets the stricter Colts Neck rule, and small shark teeth pass straight through anything coarser than 1/4 inch.
- A trowel or short scoop. A 6-inch blade satisfies both rulebooks, while a garden shovel up to 14 inches overall is legal only on the county side.
- Knee-high rubber boots or waders. County Rule 13 requires 'appropriate footwear,' and the gravel bars hide broken glass.
- A sandwich-size zip bag or small vial as your daily container. It's the county's limit, so it doubles as a measuring cup.
- A bucket to hold gravel while you screen it, so you can return it to the streambed instead of piling it on the bank
What People Find Here
- Late Cretaceous shark teeth, most commonly Scapanorhynchus (goblin shark), Squalicorax (crow shark) and Cretolamna, weathered out of the Navesink and Mount Laurel formations
- Belemnite guards (Belemnitella americana), bullet-shaped internal shells of a squid relative and probably the most distinctive Big Brook fossil
- Oyster shells including Exogyra costata and Pycnodonte, plus brachiopods and crinoid stem segments
- Fragments of ammonites, and occasional vertebrae from fish and marine reptiles (mosasaurs)
- Rarely, dinosaur bone fragments have been reported from the brook. They're scarce enough to be worth showing to the Park System naturalists.
Penalties for Violations
← Scroll to see all columns
| Violation | Statute | Penalty |
|---|---|---|
| Collecting more than five fossils a day, using oversized tools, or extracting fossils from the bank in the Colts Neck preserve | Colts Neck Code §§ 177-46, 177-48 (penalty under § 1-9); maximums set by N.J.S.A. 40:49-5 | Restoration or repair of any damaged property, plus a fine of up to $2,000, up to 90 days in jail and/or up to 90 days of community service (state maximum for municipal ordinance violations) |
| Failing to turn over archaeological items of historic significance or modern valuables found in Big Brook Park | Monmouth County Park System Supplemental Fossil Rule 9 | Violation of county park rules. Items must be surrendered to Park System staff within 48 hours through the Big Brook Park Ranger office or the Superintendent's office, 732-842-4000 ext. 4382. |
| Digging into the stream bank, damming the stream or using mechanical sifting equipment in Big Brook Park | Monmouth County Park System Supplemental Fossil Rules 3, 4 and 7 | Violation of county park rules, enforced by Monmouth County Park Rangers (732-577-8700). You can be removed from the park. |
Etiquette & Leave No Trace
- Put screened gravel back in the streambed, not on the bank
- Don't dig into the banks, even a little. Both rulebooks forbid it, and every undercut bank sends silt downstream over the gravel bars everyone else is screening.
- Share a gravel bar and leave room for the next person. On a spring Saturday there may be a dozen families at the same bend.
- Show your good finds to the county's naturalists at the Manasquan Reservoir Environmental Center (732-751-9453), which the Park System explicitly invites
- Pack out any modern trash the brook turns up, since it washes downstream to the Navesink River
- Park only in established lots, never on the shoulder of Boundary Road or Hillsdale Road
Frequently Asked Questions
Do I need a permit to hunt fossils at Big Brook?
Not as an individual, a family or a small group. Both the county and Colts Neck require no permit for small groups. The group thresholds differ: over 10 people in the county park means a Naturalist-led program, and 15 or more in the Colts Neck preserve means a $25–$50 township permit.
Is the Hillsdale Road entrance to Big Brook Preserve open?
No. Colts Neck Township posted a public notice on August 26, 2025, last edited March 5, 2026, that the Hillsdale Road entrance is 'closed until further notice' by order of the township police for public safety. Fossil hunters currently use Monmouth County's Boundary Road parking lot at Big Brook Park in Marlboro.
How many fossils can I take home from Big Brook?
It depends on which jurisdiction you're standing in. In Monmouth County's Big Brook Park you can take whatever fits in a 12-ounce can or a sandwich-size zip bag per person per day. In Colts Neck's Big Brook Preserve, § 177-46 caps it at five fossils per person per day. If you're not sure which side you're on, stick to five.
Can I dig fossils out of the creek banks?
No. Colts Neck bans extraction from the streambed walls above the waterline, and the county bans digging into the stream bank. Everything has to come from material already in the stream.
What size sifting screen is allowed at Big Brook?
No larger than 18 inches square under the Colts Neck ordinance. The county sets no screen size but bans mechanical sifters, so a hand screen of 18 inches or smaller is legal throughout.
Can I keep a dinosaur bone if I find one?
No rule at either site singles out dinosaur bone, so it counts toward the same daily limit as any other fossil. Both agencies ask you to share significant finds, though. Take a rare find to the Park System naturalists at the Manasquan Reservoir Environmental Center (732-751-9453) so it can be documented.
Is Big Brook safe for kids?
It's one of the most family-friendly fossil sites in the Northeast, but county Rule 12 warns that stream levels 'can change rapidly especially from rainfall,' and Rule 13 notes the streams contain sharp objects. Children under 14 must be accompanied by an adult who stays within sight at all times.
New to This? Start Here
Disclaimer
Information is provided for general guidance only. Regulations change frequently. Always verify current rules with the official jurisdiction before relying on this information for legal decisions. Permitted Pursuits is not a substitute for official agency guidance. Report an error.
Sources
- Monmouth County Park System — Supplemental Rules Governing the Hunting and Collecting of Fossils at Big Brook Park(accessed 2026-09-17)
- Monmouth County Park System — Big Brook Park(accessed 2026-09-17)
- Township of Colts Neck — Chapter 177, Article VII: Big Brook Preserve (§§ 177-43 to 177-48)(accessed 2026-09-17)
- Township of Colts Neck — Big Brook Preserve Rules and Policies (2019)(accessed 2026-09-17)
- Township of Colts Neck — Big Brook Preserve: Hillsdale Road Entrance Closed (public notice)(accessed 2026-09-17)
- N.J.S.A. 40:49-5 — Penalties for violations of municipal ordinances(accessed 2026-09-17)
Last verified: 2026-09-17 · Last updated: 2026-09-17