The Wall of Bones: Utah's Quarry Where 1,500 Dinosaurs Are Still in the Rock

Dinosaur National Monument’s Quarry Exhibit Hall, seven miles north of Jensen and about twenty minutes east of Vernal, is a building constructed around a single cliff face that holds roughly 1,500 dinosaur bones still embedded in the stone. You don’t look at these fossils in a display case. You walk up to a two-story wall of tilted sandstone, tan bone standing out against gray rock, and at one marked spot you can put your hand flat on a femur that has been in the ground for about 150 million years. Nowhere else in the country lets you do that at this scale.

The wall is the reason the monument exists, and the story of how it got here runs from a hunch on a Uinta Basin ridge to a steel building that once had to be torn down and rebuilt because the hillside wouldn’t hold still.

One man, one ridge, and eight tail bones

In August 1909, a paleontologist named Earl Douglass was prospecting the ridges north of the Green River for the Carnegie Museum of Natural History in Pittsburgh. His backer was Andrew Carnegie, the steel baron, who wanted a giant dinosaur for his museum and had money to spend finding one. Douglass climbed a spine of sandstone and found eight tail vertebrae of a huge sauropod weathering out of the rock in a neat row, still connected the way they’d sat in the living animal.

That was the break. The eight bones belonged to an Apatosaurus, and the ridge Douglass was standing on turned out to be a Jurassic graveyard. Over the next fifteen years he and his crews quarried the hillside hard, shipping something on the order of 350 tons of fossils east by rail — full skeletons of Apatosaurus, Diplodocus, Camarasaurus, Stegosaurus, and the meat-eater Allosaurus among them. The most complete skeleton Douglass pulled out was named Apatosaurus louisae, after Louise Carnegie, Andrew’s wife. It still stands in Pittsburgh.

Why the bones are stacked in a wall

The rock here is the Morrison Formation, the same Late Jurassic layer that produces most of the classic North American dinosaurs, dated at this site to roughly 150 million years old. Back then this wasn’t desert. It was a broad river plain, and the quarry sits on what was once a sandbar. When animals died upstream, floods washed the carcasses downriver and dumped them where the current slowed, the way a flooded creek piles driftwood on a bend. Bones from dozens of animals ended up jumbled together in one sandbar, then buried, mineralized, and slowly tilted upward as the mountains rose. That’s why the wall is steep — the whole bone bed got rotated toward vertical over millions of years.

Douglass wanted people to see the bones this way, in place, instead of hauling every last one to a museum. He pushed for the site to be protected, and on October 4, 1915, President Woodrow Wilson signed the proclamation creating Dinosaur National Monument — at first just 80 acres around the quarry. In 1938 Franklin Roosevelt expanded it to more than 210,000 acres, pulling in the wild river canyons of the Green and the Yampa that most people now associate with the name. But the original 80 acres, the bone wall, is still the heart of it.

The building that slid

Rather than dig the last bones out, the Park Service made an unusual call in the 1950s: leave about 1,500 of them half-exposed in relief on the quarry face and build a visitor hall right over the top. The original structure went up in the late 1950s and became one of the most photographed rooms in the National Park System.

Then the ground moved. The hall sat on expanding clay soils that swelled and shifted with moisture, and by 2006 the building had racked and cracked badly enough that the Park Service closed it as unsafe. For five years the wall sat behind a shuttered building. Crews eventually tore down the failed structure, re-engineered the foundation to ride out the moving soil, and reopened a rebuilt Quarry Exhibit Hall in October 2011. That’s the hall you walk into today, and the bones behind the glass are the same ones Douglass chose to leave in the rock.

What you actually see inside

The centerpiece is the wall itself: roughly 1,500 bones, tan against the gray sandstone, from at least ten kinds of dinosaur. Rangers and signs point out the standouts — the long neck bones of the sauropods, the plates and spikes of a Stegosaurus, the serrated teeth marks and claws of Allosaurus. The upper level puts you at eye level with the top of the wall; the lower level has the touchable fossils, a stretch of real bone the Park Service lets visitors put their hands on. For a lot of kids, and plenty of adults, that’s the moment the whole thing stops being an abstraction.

How to visit, and the honest part

The Quarry is in Utah’s far northeast corner, and there’s no getting around the drive — it’s about three hours from Salt Lake City and three and a half from Provo, most of it across the Uinta Basin. Vernal is the base town, twenty minutes west, and it’s where you’ll find lodging, gas, and food. Don’t count on either at the monument itself.

You reach the Quarry Exhibit Hall from the Quarry Visitor Center off Utah Highway 149. In the busy summer season the Park Service runs a shuttle up the short hill to the hall; in the quieter months you’re allowed to drive your own car up. Summer hours generally run 8 a.m. to 6 p.m., with the exhibit hall closing about half an hour before the visitor center; spring, fall, and winter hours are shorter, so check the day you go. Access has been touchy lately — the hall closed for several weeks in fall 2025 for a full road, parking, and sidewalk rebuild — so confirm it’s open before you commit to the drive.

One more thing worth setting straight: the bone wall is on the Utah side, but the monument straddles the Utah–Colorado line, and the fossils and the river country are two different trips. If you’ve come for the Wall of Bones, aim for Jensen, Utah, not the town of Dinosaur, Colorado, on the far side. The rafting canyons in the Green and Yampa river country are spectacular, but they’re a different day.

Is it worth three hours each way to look at a wall? For most people who make the drive, standing in front of 1,500 bones that a river buried before the Rockies existed answers that on its own.