Dinosaur National Monument, a few hours away from Provo UT, preserves and protects one of the most extensive dinosaur bone beds in the world.
For those who don't know, I live in a converted campervan and travel around the country, posting photo diaries of places that I visit.
Around 150 million years ago, during the Jurassic period, a large number of dinosaurs were killed in a series of flash floods that swept through a shallow river delta in what is now eastern Utah. The drowned corpses were covered with mud and silt and were, over time, fossilized where they lay.
This happened several times over a long period, with each layer being covered and fossilized. As the Rocky Mountains were uplifted, these rock layers were tilted upwards until they are now almost vertical.
In 1908, fossil hunter Earl Douglass, who was working for the Carnegie Museum of Natural History in Pittsburgh, reached a remote area near the Green and Yampa Rivers, part of the Morrison Formation which had been briefly explored a few years earlier by prospectors from the American Museum of Natural History. While looking for fossils, he happened to find some bones eroding out of the ground. They turned out to be vertebral bones from a giant plant-eating sauropod dinosaur which was then called Brontosaurus and is now known as Apatosaurus. Digging further, Douglass concluded that he had not only found a partial skeleton, but that there was more than one. Then more bones uncovered, and more, and still more. It was a large bone bed.
The site became dubbed the “Carnegie Quarry”, and Douglass and other diggers from the Carnegie Museum would spend the next 15 years here, with Carnegie budgeting $5,000/year. During that time, they uncovered thousands of individual bones, all jumbled together and overlapping each other. There were around twenty partially-complete skeletons excavated, and by carefully fitting other bones to these, Douglass was able to assemble 11 complete specimens, including Apatosaurus, Barosaurus, and Allosaurus. These, along with other recovered bones, were shipped back to the Museum by a specially-laid railroad track at the edge of the quarry.
By 1923, Andrew Carnegie had died, the Carnegie Museum was cutting back on its work at the Quarry, and teams from several other museums continued excavating every so often, but for the most part, work ceased. The fossil bed, over 100 yards long, still contained thousands of bones embedded in the hard sandstone.
The mounted skeletons from the Quarry found their way to a number of different museums. The initial Apatosaurus found by Douglass (still the most complete example of this species ever found) was displayed at the Carnegie Museum next to the famous Diplodocus. Although a skull had been found near it, there was disagreement about whether it belonged to the skeleton, so a Camarasaurus skull was mounted to it instead. It wasn’t until 1979 that paleontologists agreed that the original skull was correct, and the Apatosaurus finally received its own head.
In 1912, another skeleton was found, which was identified as a Diplodocus. Pieces of it went to a number of different museums. Then paleontologist Barnum Brown of the American Museum of Natural History examined it and re-identified it as a Barosaurus, and gathered all the pieces together for display in New York. It is now on exhibit in the Museum’s atrium.
The next year, pieces of a very large Allosaurus, a two-legged meat-eater, were found, and soon a nearly-complete skeleton was unearthed. This skeleton, with its skull swapped out for a more-complete specimen from the University of Utah, went on display in Pittsburgh in 1938. It is still there.
Some of the species from the Carnegie Quarry that went to display or study collections at various museums were Stegosaurus, Camptosaurus, Camarasaurus, Dryosaurus, Laosaurus, Antrodemus, Ceratosaurus, Torvosaurus, and Diplodocus. Extinct crocodile and turtle bones have also been found, along with clam shells and small animals.
Back in 1915, the Director of the Carnegie Museum, William Holland, had convinced President Woodrow Wilson to designate the site as a National Monument. Douglass had by that point only excavated a tiny proportion of the bone bed, and in 1923, he proposed that a large section be preserved as it lay, so the public could see the bones as they were actually uncovered: "I hope that the Government, for the benefit of science and the people, will uncover a large area, leave the bones and skeletons in relief and house them in. It would make one of the most astounding and instructive sights imaginable."
During the 1930s the area protected by the site was expanded by President Franklin Roosevelt to include some Native American cultural sites, and some work was done at the park by the Works Progress Administration, including some buildings and a walkway. In the mid-1950s the park was threatened by a proposed hydroelectric dam, but conservationists successfully fought to end that project. In 1958 construction finally began on an immense structure that covered about half of the remaining fossil bed, protecting it from the elements. It became Dinosaur National Monument.
Today, the park extends from Utah into Colorado for over 300 square miles. In addition to the “Wall of Bones” bone bed, the park contains ancient archaeological sites that were inhabited by the Native American Fremont Culture and several areas containing ancient petroglyphs.
Some photos from a visit.