Utah’s Dinosaur Boneyard Still Yields Treasure

Ann Schaffer is keeper of one of the world’s prime dinosaur boneyards.

Wearing white coveralls, she chips away at the steep, 190-foot-long, 30-foot-high sandstone cliff inside Dinosaur Quarry Visitor Center, exposing bones of giant prehistoric beasts.

There isn’t a similar wall of dinosaur bones on exhibit anywhere. So far, 2,200 bones representing about 200 individual dinosaurs have been exposed.

“It’s exciting work,” said Schaffer, 28, who received her master’s degree in geology from Utah State University. “Every time I encounter a new bone on the wall, I am the first person to see it since that dinosaur died about 145 million years ago.”

As the 5-foot-3 Schaffer uncovers dinosaur bones with the tools of her trade--a 90-pound jackhammer, drills, wedges, chipping hammers, chisels and ice picks--she said her mind often wanders back to when the huge animal thrived in this part of Utah.

“I think about what it must have been like around here with brontosauruses three times the size of today’s biggest elephants grazing in the wild,” she mused.

“Or what it was like when sharp-clawed, carnivorous allosaurus ripped into other giant animals to satisfy hunger. I can just imagine the bizarre stegosaurus with huge triangular bony spiked backs and tails and all the other strange prehistoric creatures running around.”

Every year thousands of visitors come to the Dinosaur Quarry, seven miles north of the tiny town of Jensen in Utah’s northeastern corner.

Scientists come to study the exposed skulls and bones embedded in the wall. Paleontologists also travel here to view the skeletal remains from the quarry that are kept on shelves in the National Monument’s scientific lab.

Since its discovery in 1909 by paleontologist Earl Douglass, the quarry has produced an unequaled number of dinosaur bones. He searched for two years in the rainbow-hued sandstone cliffs of Split Mountain before he found the first indication that he was working above one of the most outstanding dinosaur cemeteries ever encountered.

On Aug. 17, 1909, Douglass noted in his diary: “At last in the top of the ledge where the softer overlying beds form a divide, I saw eight of the tail bones of a brontosaurus in exact position. . . .”

Well-Preserved Specimens

Several of the best-preserved specimens of Jurassic Period (136-193 million years ago) dinosaurs have been found here.

How did the bones get on the upturned cliff inside the Dinosaur Quarry Visitors Center?

It is believed that the carcasses of the dead dinosaurs washed downstream in a huge, winding river and lodged against the sandbar. In time the animals were buried by river sands and gravels, cementing into hard sandstone, the bones fossilized within it.

Millions of centuries passed and the 15-foot-thick bone-bearing layer was covered with sand, sediments, rock and other soil a mile deep. The sandstone layer was upended by pressure. Eventually, erosion wore away the top cover, exposing the tail bones of the brontosaurus discovered by Douglass.

He had come to Utah’s Green River country because of the proliferation of Morrison Formation Rock, the same formation where dinosaur bones had been found earlier in Wyoming and Colorado. His expedition was financed by Andrew Carnegie, who wanted dinosaur skeletons to fill his new museum in Pittsburgh.

For 15 years, Douglass and his party dug out and transported 350 tons of dinosaur bones from the 600-foot-long, 80-foot-deep trench. Skeletons from the quarry now stand in the Carnegie Museum, the Smithsonian and other notable collections.

When President Woodrow Wilson designated the quarry a national monument in 1915, Douglass proposed that one wall of the trench be set aside as an exhibit.

But the National Park Service did not have the funds to carry out Douglass’ dream in 1915, nor for the next 38 years. The paleontologist died in 1931.

In 1953 work finally began on Douglass’ dream to excavate a wall, leave the bones in place and construct a building around the exhibit. The Dinosaur Quarry Visitor Center opened in 1958.

Tobe Wilkins worked 34 years and Jim Adams worked 30 years chipping away at the wall exposing the bones. When Adams retired two years ago, Ann Schaffer was hired to take his place. Wilkins retired three months ago.

On Schaffer’s two days off, Lorraine Ferris, 33, wife of the quarry’s resident paleontologist, Dan Chure, 33, works on the wall.

Many visitors ask them questions as they peck away at the ever-growing giant jigsaw puzzle on the sandstone cliff.

A Good Guess

“Are those bones of a brontosaurus?” asked Kurtis Bradley, 6, pointing to a series of tail vertebrae.

“You got it,” Schaffer shouted back.

More juvenile dinosaurs--baby dinosaurs the size of a pony--have been found in this quarry than anywhere else.

Dinosaur skulls are hard to come by, yet 14 have been found here. Even the skull of a camarasaurus is frozen in an eerie grin high on the quarry wall.

“The great thing about working on the wall is you never know what you’re going to find next,” Schaffer said. “There could be bones of a never-before-seen dinosaur just waiting to be exposed.”