National park · United States
Fossil Butte National Monument
Give it 2–3 hours: the visitor centre fossils first, then the 4 km (2.5 mi) Historic Quarry Trail if the weather holds. Free entry; the quarry dig is only Fri–Sat 11:00–16:00 in summer.Give it 2–3 hours: the visitor centre fossils first, then the 4 km (2.5 mi) Historic Quarry Trail if the weather holds. Free entry; the quarry dig is only Fri–Sat 11:00 AM–4:00 PM in summer.Give it 2–3 hours: the visitor centre fossils first, then the 2.5 mi (4 km) Historic Quarry Trail if the weather holds. Free entry; the quarry dig is only Fri–Sat 11:00–16:00 in summer.Give it 2–3 hours: the visitor centre fossils first, then the 2.5 mi (4 km) Historic Quarry Trail if the weather holds. Free entry; the quarry dig is only Fri–Sat 11:00 AM–4:00 PM in summer.
- Source checked
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- Field checked
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- Plan calculated
- Worked out by Voykit from its own data (times, distances, budgets). A calculation, not a measurement.
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Map to the park
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Area
34 km² (13 sq mi)13 sq mi (34 km²)
approximate
Established
1972
Best months
May–Jun, Sep
UNESCO
None
Rules in force · 7Crossing between the US, Canada and Mexico by land needs …Cannabis is legal in Canada and in many US states, but ta…
- North America ↗Crossing between the US, Canada and Mexico by land needs your passport even on a day trip; rental cars need the company's written permission to cross, and most US and Canadian rental insurance stops at the Mexican border.
- North America ↗Cannabis is legal in Canada and in many US states, but taking any amount across the US, Canadian or Mexican border is a federal crime — including edibles and vapes.
- North America ↗The busiest US and Canadian national parks need timed-entry, campsite or lodge reservations in summer; release dates are months ahead.
- United States ↗Check whether you need an ESTA (Visa Waiver Program) or a visa on the official CBP and State Department sites; apply only through esta.cbp.dhs.gov, not third-party sites, and allow time before you book.
- United States ↗Several popular national parks use timed-entry or vehicle reservations in peak season; check each park's page on nps.gov and book on recreation.gov before fixing your dates.
- United States ↗Medical care is very expensive for visitors; buy travel insurance with high medical cover before you fly.
- United States ↗Tipping is expected: about 15–20% at sit-down restaurants and bars, and a tip for taxis, hotel staff and guides.
At a glance
- Country
- United States
- Area
- 34 km² (13 sq mi)13 sq mi (34 km²)
- About 33.8 km² (13 sq mi) of sagebrush bench and butte country (check).
- Established
- 1972
- Best months
- May–Jun, Sep
- Permits
- For some areas
Fossil Butte protects a slice of a 50-million-year-old subtropical lake bed in the Green River Formation, where fish, turtles, bats, insects and dog-sized horses were buried so fast that soft tissue and stomach contents survived. The National Park Service runs the site as a day-use monument: a free visitor centre with more than 300 specimens, two short trails up the butte, and a working research quarry that staff split open in front of visitors on summer Fridays and Saturdays. It is a two-to-three-hour stop on US-30 west of Kemmerer, not a park you build a trip around — pair it with the Wyoming Range and the Idaho border country, or use it as a break on the long drive between Jackson and Salt Lake City.
Decide
Why go, which months, and what lives here when
At a glance
Status
- No UNESCO listing; national park since 1972.
Size and age
34 km² (13 sq mi)13 sq mi (34 km²) · national park since 1972
About 33.8 km² (13 sq mi) of sagebrush bench and butte country (check).
Why go
- One of the best windows into a 50-million-year-old subtropical lake: fish, turtles, bats, insects and dog-sized horses preserved in the Green River Formation.
- The fossil quarry is worked in front of visitors on summer Fridays and Saturdays, so you watch preparation rather than just read labels.
- Free entry and a short, well-marked trail network — an easy half-day between Kemmerer and the Idaho line.
- The 2.5-mile Historic Quarry Trail climbs to the actual dig sites, with wide views over the Hams Fork valley.
When to go
- JanAvoid
- FebAvoid
- MarCaution
- AprCaution
- MayBest
- JunBest
- JulGo
- AugGo
- SepBest
- OctGo
- NovCaution
- DecAvoid
- JanDaytime −29 to −1 °C (−20 to 30 °F); roads and trails snowboundDaytime −20 to 30 °F (−29 to −1 °C); roads and trails snowbound
- FebCold and windy; visitor centre closed Sundays and Mondays
- MarCentre reopens daily mid-month; snow patches on trails
- AprMuddy trail, cold wind; centre daily
- MayCentre on summer hours; trails drying out
- JunLong days, quarry digging on Fri–Sat
- JulWarm to hot; afternoon thunderstorms possible
- AugWarm; start early to beat heat and wind
- SepCool, clear, quiet; quarry season ends
- OctCrisp; centre shifts to shorter hours late in month
- NovCentre closed Sundays and Mondays from late Nov; snow starts
- DecDeep cold; limited access
Wildlife and nature calendar
| What | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Pronghorn and mule deer on the sagebrush benchApr–Jun, Sep–Oct · Dawn and dusk; stay in the car or keep distance. | no | no | no | yes | yes | yes | no | no | yes | yes | no | no |
| Golden eagles and hawks riding the ridge liftMar–May, Sep–Oct | no | no | yes | yes | yes | no | no | no | yes | yes | no | no |
| Sage grouse and other sagebrush birdsApr–May | no | no | no | yes | yes | no | no | no | no | no | no | no |
| Rattlesnakes on the lower trailMay–Sep · Watch where you put hands and feet; give them room. | no | no | no | no | yes | yes | yes | yes | yes | no | no | no |
Arrive & move
Getting in, how the park is divided, and where things are
Show 3 sectionsHideHow to get there, Zones and sectors, Sketch map
How to get there
From Kemmerer, WY
US-30 west about 24 km (15 mi) to the Chicken Creek Road turn, then a short climb to the visitor centre.US-30 west about 15 mi (24 km) to the Chicken Creek Road turn, then a short climb to the visitor centre.
25 min
From Jackson, WY
US-189 south through the Salt River pass, then US-30 south-west; long drive with few services.
3.5–4 h
From Salt Lake City, UT
I-80 east to Evanston, then WY-150/US-189 south to Kemmerer and US-30 west.
3.5–4 h
From Idaho Falls, ID
US-26 east to Alpine, then US-89 and US-30 south through Afton and Cokeville.
3–3.5 h
Zones and sectors
| Zone | What is there | Access |
|---|---|---|
| Visitor centre bench | Exhibits of more than 300 fossils, films on excavation and preparation, restrooms and picnic tables. | Open with seasonal hours; free. |
| Historic Quarry Trail | The main walk, climbing past old quarry pits to the working research quarry. | Open; no permit; snowbound in winter. |
| Nature Trail | A shorter loop through sagebrush and aspen below the centre. | Open; easy. |
| Research quarry | Active excavation area where the Green River Formation layers are split. | Viewable from the trail; digging only with NPS staff, summer Fri–Sat. |
Sketch map
Take the points offline
5 points as a GPX waypoint file, plus a plain-text list of coordinates. Save it while you have signal: maps apps show the points without a connection.
Monument coordinates from the official listing; trail and quarry points are approximate, for orientation only.
See & do
Caves, trails and wildlife, with how hard each is and whether it needs booking
Show Top experiencesHide
Top experiences
Practical
Fees, permits, rules, where to sleep and what can go wrong
Show 8 sectionsHideEntry fees and permits, Park rules, Where to stay, Safety, Accessibility, Visiting lightly, Questions people ask, Related
Entry fees and permits
| Item | Range | Per | Note |
|---|---|---|---|
| Entrance to the monument and visitor centre | Free | person | No entrance fee; this is a National Monument managed by the National Park Service (check current status). |
| America the Beautiful annual pass | US$80 | year | 2026 estimate; not needed here, but pays off across fee-charging parks on the same trip. |
| Guided school or group program | Free | group | Reservations through the visitor centre; no set fee published (check). |
Ranges, not quotes: fees change without notice. Check with the park or your operator · checked Sep 2026.
Monument entry no permit
Fossil collecting permit or guide
Group or school visit permit or guide
Park rules
- Fossil collecting
- Removing fossils, rocks or plants is prohibited; leave everything where it lies.
- Drones
- Launching drones is not allowed on National Park Service land without authorisation (check).check
- Pets
- Keep dogs leashed and off the trails; they are not allowed on the Historic Quarry Trail.
- Stay on trail
- Do not enter the quarry pits or dig into the slopes; the layers are fragile and the ground unstable.
- Fires and camping
- No camping or fires in the monument; it is a day-use site.
Where to stay
Near the park
Kemmerer
Motels and a few inns, about 25 min from the visitor centre; the practical base.
Near the park
Cokeville and Afton
Small-town lodging on the Idaho side of the route, 45–90 min away.
Near the park
Diamondville and Evanston
More rooms along US-30 and I-80 if Kemmerer is full.
Safety
Winter cold and snow high
Exposure on the quarry trail medium
Rattlesnakes medium
Long drives with no services medium
How much daylight do you have?
Time out
Finding the local time zone…
Times are local to the spot (zone loading). The half-hour margin is our rule of thumb, not an official figure; light fades earlier in forest or under cloud. Carry a headlamp on any route that could run late.
Accessibility
- The visitor centre, exhibits, restrooms and picnic area are step-free and reachable by car.
- The Nature Trail is the easier surface; the Historic Quarry Trail is rough, steep in places and not suitable for wheelchairs or strollers.
Visiting lightly
- Leave fossils and rock fragments in place — every removed piece is data lost from the site.
- Pack out all rubbish; there are no bins on the trails.
- Carry water in refillable bottles rather than buying single-use plastic in town.
Questions people ask
How much does it cost to enter Fossil Butte National Monument?
Nothing. There is no entrance fee and no reservation; you drive in and park at the visitor centre. The America the Beautiful annual pass (2026 estimate US$80) is only worth buying if you are also visiting fee-charging parks on the same trip.
What are the best hikes in Fossil Butte National Monument?
The 4 km (2.5 mi) Historic Quarry Trail is the main walk, climbing about 100 m past old diggings to the working quarry. The 2.4 km (1.5 mi) Nature Trail is the shorter, easier loop. Both are exposed and snowbound in winter.
When is the best time to visit Fossil Butte National Monument?
May, June and September. Days are mild, the visitor centre is on full hours and the trails are usually dry. July and August are hotter with afternoon storms; December to February is deep winter with limited access.
Can I dig for fossils or take one home?
No. Collecting is prohibited and the quarry is worked only by staff under permit. On summer Fridays and Saturdays, 11:00–16:00, you can watch excavation and preparation at the research quarry.
How long do I need at Fossil Butte?
Two to three hours covers the visitor centre and the Historic Quarry Trail. Add an hour if you catch the summer quarry digging, and allow 25 minutes each way from Kemmerer.
Is there food or fuel at the monument?
No. There is a picnic area but no shop, restaurant or fuel. Eat and fill up in Kemmerer, about 24 km (15 mi) east on US-30.
Deep dive
Every source; fees and rules change, so check before you go