Quarry Exhibit Hall

The Quarry Exhibit Hall at Dinosaur National Monument in Utah is home to a large wall containing more than 1,500 fossils. Some of the species that may be spotted are the Allosaurus, Apatosaurus, Camarasaurus, Diplodocus, and Stegosaurus. But the bones on this wall weren't arranged by any curator or paleontologist—they were deposited by an ancient stream more than 150 million years ago.

In 1909, paleontologist Earl Douglass uncovered eight segments of a large dinosaur tail at the top of a steep sandstone cliff in Utah. This discovery—which turned out to be tail segments from an Apatosaurus—was the first of many at the site. It quickly became clear how many treasures were buried at the dinosaur quarry, and just a few years later, in 1915, Dinosaur National Monument was established to protect the land. Over decades of excavation, scientists found a huge number of bones, including some complete skeletons.

The "Wall of Bones" inside the Quarry Exhibit Hall consists of a steeply tilted layer of rock filled with fossils, just a portion of what was at the site when Douglass first arrived. A small metal building was constructed around this portion of rock in 1951, and later expanded into a larger structure with a modern glass and steel design. In 2006, the Quarry Visitor Center closed—unstable clay beneath the building led to a number of structural problems. Eventually, the National Park Service rebuilt the hall atop steel beams that extended into the bedrock beneath the clay. It reopened to visitors in 2011.

The building has two levels and glass walls to allow natural light to stream in, so visitors could watch technicians at work, removing bits of rock to reveal the fossil bones embedded within. Below the viewing balcony is an 80-foot (24.3-meter) mural that features depictions of some of the more notable dinosaurs of which fossils are showcased along the wall.