"America's aquarium in stone" — exquisite fossil fish in high Wyoming.
Photo: Didier Descouens · CC BY-SA 4.0 · via Wikimedia Commons
In the high sagebrush-steppe of southwestern Wyoming, a layered butte holds the remains of an ancient subtropical lake — Fossil Lake — that, about 52 million years ago, buried fish and other life over some two million years in sediment so fine it preserved them in astonishing detail. Fossil Butte National Monument protects part of that lake bed, often called "America's aquarium in stone," with one of the finest fossil collections you can see anywhere.
It's free, and the visitor center is the must-see: fish preserved down to the fin rays, alongside a stingray, gar, turtles, birds, bats, an early horse, a 13-foot crocodilian, insects and plants, plus a working preparation lab. What you can't do is dig — collecting is against federal law, and nothing is exposed along the trails. What you can do is walk the Historic Quarry Trail, a 2.5-mile loop up past a fossil hunter's 1918 cabin to a spur reaching the historic quarry. And on summer Fridays and Saturdays, rangers run a drop-in program at the park's Research Quarry, the one place you'll watch paleontologists actually working the rock.
Lead with the weather: the visitor center sits near 6,700 feet and the monument climbs to about 8,000, so this is cold, windy, high-desert country where even summer nights drop into the low 40s and there's no shade. Summer (June–August) is the season, and you'll still want layers. The 5.5-mile Scenic Drive is seasonal — closed to vehicles by about 1 November, usually reopening in late May. It's remote, so fuel up in Kemmerer, 13 miles east. Pair it with Flaming Gorge to the south-east or the Tetons to the north.
Fossil Butte sits off US-30 in south-west Wyoming, a few miles from Kemmerer and a long way from anything else. There is a short scenic drive and a visitor center full of some of the best-preserved fossil fish anywhere, and the real driving story is the empty country you cross to reach it.
Nine miles west of town, then right onto County Road 300 and north on Chicken Creek Road to the visitor center — about 13 miles and 20 minutes all in. Paved, signed and easy; the effort is in getting to this part of Wyoming at all.
Starts just outside the visitor center parking lot. Paved for 2.5 miles to the Nature Trail lot, then gravel with a 17% grade for three more miles up to the ridge. RVs and anything towing should turn around at the Nature Trail lot. Closed to vehicles by about 1 November and reopened once the snow melts, usually late May.
Ten wayside signs work up from the entrance sign to a ridge-top panorama over the basin, with unmaintained trailheads for Cundick Ridge, Eagle Nest Point and Rubey Point off the gravel section. Allow an hour there and back.
TipTurn around at the top — cattle guards mean you have left the monument onto BLM roads that want four-wheel drive and a map from the BLM office.
More than 2,000 Green River Formation fossils indoors — exquisitely preserved fish, plus a stingray, gar, turtles, birds, bats, an early horse, a 13-foot crocodilian, insects and plants — with a working research and preparation lab.
Insider tipThe heart of the visit: fossils aren't visible on any trail, so this is where you actually see them. Hours shift with the season (8:00–5:30 in summer, 8:00–4:30 the rest of the year, closed Sundays from November through April), so check before driving out.
Plan a trip to this spot →A 2.5-mile loop climbing about 700 feet from a 6,675-foot start, past David Haddenham's 1918 fossil-hunter's cabin, with a short spur up to the historic quarry and several flights of stairs near the top.
Insider tipIt has its own trailhead, half a mile in off US-30 on County Road 300 — not at the visitor center. Open year-round, but snowy or muddy from fall through spring. No shade: carry water and start early.
Plan a trip to this spot →The layered butte that holds the world-famous fossil layers, rising above the surrounding steppe.
Insider tipThe benches on the Nature Trail and the top of the Scenic Drive give the best long looks at the rock layers; the Historic Quarry Trail puts you on the butte itself.
Plan a trip to this spot →Two unmaintained routes off the gravel upper half of the Scenic Drive — Cundick Ridge and Eagle Nest Point from the first pullout, Rubey Point from the second — climbing into open high steppe above the basin.
Insider tipUnmaintained means no signs and no tread in places, so take a map and give yourself daylight. Neither route is a quick stroll from the car.
Plan a trip to this spot →About 52 million years ago a subtropical freshwater lake here buried fish and other life in fine sediment over ~2 million years, preserving them in extraordinary detail — "America's aquarium in stone."
Insider tipRead the visitor-center exhibits first — they make the trail and the butte's layers far more meaningful.
Plan a trip to this spot →The 1.5-mile Nature Trail loop climbs about 300 feet from the picnic area at 7,000 feet, through sagebrush and a spring-fed aspen grove, with benches looking back at Fossil Butte. Pronghorn, mule deer, jackrabbits and ground squirrels are what most visitors actually see.
Insider tipDawn and dusk are best for wildlife. The picnic area is 2.5 miles up the paved part of the Scenic Drive — and it is where RVs and trailers should turn around.
Plan a trip to this spot →High, cold sagebrush-steppe: the visitor center sits near 6,700 feet and the monument reaches about 8,000. Summers are short, cool and dry — the best season — with warm days but cold nights, July and August lows still in the low 40s. Winters are long and snowy, with December through February highs in the high 20s and low 30s. Persistent wind, big day-night swings, and no shade on the trails. Pack layers any season.
Off US-30 west of Kemmerer — free, remote, high.
Nine miles west of Kemmerer on US-30, then right onto County Road 300 and north on Chicken Creek Road — about 13 miles and 20 minutes from town. No entrance fee, no pass, no reservation. Salt Lake City is about 150 miles and 2½ hours south-west; Grand Teton is about 3 hours north. Remote and high — fuel up in Kemmerer, bring water, and expect patchy cell service (there is wifi at the visitor center).
No lodging or camping in the monument — stay in Kemmerer.
The practical base, about 13 miles east — motels, fuel and dining, plus the JCPenney Mother Store and the Hamsfork Museum.
Booking tipClosest services.
Camping is not allowed inside the monument. Dispersed camping is permitted on the surrounding BLM and Forest Service land — ask at the visitor center or the BLM Kemmerer field office for directions — and there are a handful of first-come sites at Viva Naughton Reservoir about 16 miles north of town.
Booking tipLarger lodging is farther toward Evanston or the Tetons.
Is it free?
Yes — no entrance fee, no pass and no reservation required.
Where do I actually see the fossils?
In the visitor center, which displays fish, a stingray, gar, turtles, birds, bats, an early horse, a crocodilian, insects and plants, plus a working prep lab. Nothing is exposed along the trails, and collecting anything is against federal law.
What's the main hike?
The Historic Quarry Trail, a 2.5-mile loop with about 700 feet of climbing up to the historic quarry, passing a 1918 fossil-hunter's cabin. Note its trailhead is off US-30, not at the visitor center. The gentler option is the 1.5-mile Nature Trail loop, 2.5 miles up the Scenic Drive.
Can I see a real dig?
In season, yes. Rangers run a drop-in Fossil Quarry Program at the park's Research Quarry on Fridays and Saturdays from late June to mid-August, 11am to 3pm, and no reservation is needed. It is a three-quarter-mile hike with over 300 feet of climb, and there is no shade, water or restroom at the quarry — get directions at the visitor center first. Digging on your own is not allowed anywhere in the monument.
How cold and high is it?
High and cold. The visitor center is near 6,700 feet and the monument reaches about 8,000. Even summer nights are cold (July and August lows in the low 40s); days are warm but the sun and altitude are intense, the trails have no shade, and it is windy. Winters are long, cold and snowy.
How remote is it?
Quite. It is nine miles west of Kemmerer on US-30 and a few more miles in on county roads, with no food, no fuel and no camping on site. Cell service is patchy, though there is wifi in the visitor center. Fill the tank and pack water and snacks in town.
When should I go?
Summer (June–August). That is the mildest weather, the season for ranger programs, and the only time the full 5.5-mile Scenic Drive is open — it closes by about 1 November and usually reopens in late May. Spring and fall are short and chilly; winter brings snow, Sunday visitor-center closures, and no drive.
Pick your vehicle, line up the stops on the way in and out, and carry the whole route in your pocket.
