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The Dinosaur Quarry NPS logo

History and Development of the Quarry


No one knows how long the old bones had been weathering out of the hills of what is now Dinosaur National Monument before the first man saw them. Curious Indians, wandering between the upturned ridges of Mesozoic rocks, picked up fragments and carried them off to their camps where they are now found among the arrow points; ax heads, and corn-grinding stones. In 1776, the Spaniard, Father Escalante, passed within sight of today's dinosaur quarry, not dreaming of the antiquity hidden there. Maj. John Wesley Powell, on his second voyage down the Green River in 1871, recorded the presence of "reptilian remains" in the area, but wrote nothing more about them. Sheepherders, cattlemen, and hunters observed them and were impressed in proportion to their understanding. But, through all the years, the nature of the bones remained a mystery.


Then, in 1893, this mystery was solved. O. A. Peterson, a scientist from the American Museum of Natural History, while conducting field work in the Uinta Basin to the south of the present monument boundaries, discovered bones out-cropping from a recognized fossil-bearing stratum. The stratum was the 140,000,000 year-old Morrison formation. The bones? Peterson reported them as the remains of dinosaurs.

That report was to have an important influence, 15 years later, in directing a fellow paleontologist from the Carnegie Museum in Pittsburgh to investigate the area. Earl Douglass was the paleontologist's name. In 1908, he and W. J. Holland, Director of the Carnegie Museum, found themselves in the region of Peterson's discovery, searching for dinosaur remains. They extended their search to the north and thence along the Morrison hogback that flanks Split Mountain. Bone was found—not much, but enough to bring Douglass back the following summer and in company with George Goodrich, a local resident, to pursue the hunt.

The hunt came to a triumphant climax on August 17, 1909, when—to quote from Douglass's 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 [Apatosaurus] in exact position."

. . . I SAW EIGHT OF THE TAIL BONES OF A Brontosaurus IN EXACT POSITION." (from Douglass' Diary, 1909. Shown in photo is Douglass assistant, Elder Goodrich.)


This was the beginning—the beginning of the celebrated dinosaur quarry which was to yield such a multitude and variety of ancient forms to science, and eventually lead to the establishment of Dinosaur National Monument.

Douglass proceeded to dig into the solid rock along those original eight tail bones and found other parts of the skeleton. In time, the almost complete frame of the Apatosaurus was exposed. The skull was missing and parts of the limb bones, but this was to be expected, as fossil vertebrates are rarely preserved in their entirety. What was not expected were the remains of a smaller dinosaur comingled with those of its huge contemporary.

THE FIRST CUT IN THE QUARRY, AS IT LOOKED IN 1910. (Courtesy, A. S. Coggeshall.)


Douglass was elated. This was more than a "one strike"! How much more, only further digging would tell. Sensing a large-scale operation, he informed the Carnegie Museum of his prospects and readied things with the intensity of a man at the gate of destiny. From the neighboring ranches he recruited men, horses, and equipment. He sent for his wife and child. He constructed a road to the discovery site, built a five-room cabin out of logs and lumber, converted a sheepherder's camp wagon into an office, selected ground for future planting, bought a cow. A forge was set up. Tools were purchased.

Back at the museum, Andrew Carnegie, himself evinced interest. He had always wanted something "as big as a barn" for his institution. A special annual field fund of $5,000 was added to the regular budget to carry on the work.

Within a year, Douglass and his men had run a cut over a hundred feet long in the hard sandstone, digging down along the almost perpendicular slant of the rock. Ar the base of this, rails were laid and small mine carts introduced to haul away the cuttings from the rapidly developing quarry.

New specimens appeared: A small plant-eating dinosaur known as Dryosaurus; an armored form called Stegosaurus; and another large creature like the Apatosaurus. Best of all, the Apatosaurus No. 1 was well on its way out of the rock and would soon be ready to ship to the Carnegie Museum in Pittsburgh.


In 1913, after 5 years of laboratory work in the Carnegie Museum the big Apatosaurus was on its feet in the Hall of Vertebrate Paleontology—1 of the 4 mounted specimens of this genus in the country and the most perfect of all. Prepared and erected by Arthur S. Coggeshall and his associates, it measures 71-1/2 feet long and stands 15 feet tall at the arch of the back.

As the excavating progressed it was not long before the diggings became what is known to the profession as a "general quarry." Dinosaurs of "all kinds and sizes" were showing up. Other quarries of this type had been developed in previous years in the Morrison formation at Como Bluff, Wyo., and Canon City, Colo., but they contained nothing like the variety of forms found here. Moreover, these at the monument were better preserved and the skeletons more intact.

The remains most frequently encountered in the diggings were those of sauropods—the huge plant-feeding dinosaurs with long tapering extremities that lumbered about on four pillar-like legs. Camarasaurus and the larger Apatosaurus were typical members of this group, and their numerous bones show them as being common animals of their time.

More common were the Diplodoci, of the exaggerated neck and even longer whiplash tail. This genus distinguished itself by producing not only the largest amount of skeletal material from the quarry, but also the largest number of skulls—those rarest of fossils. One skull was found in exact position with the neck bones, which settled all doubts as to the details of this animal's head piece. The longest Diplodocus to come from the monument extended 75-1/2 feet.


Contrast this with the diminutive Laosaurus, a 2-1/2-foot biped which ranks as the smallest dinosaur yet taken from the deposit. This tiny creature had hollow limb bones and was one of the agile, quick-running types. Only one was found. When discovered, Douglass thought it a "baby" dinosaur, but study proved it to be a full-grown specimen. The condition of the skeleton reflected considerable agitation before and after burial. It lay on its back, the limbs distended. The tail was gone and the skull crushed.

In many respects, the most interesting dinosaur found was the sauropod, Barosaurus. It was an extremely long-necked form, some of the individual cervical vertebrae measuring 3 feet in length. Two specimens were excavated.

The flesh-eaters, as might be expected from their scarcity in other localities, made but a small showing. Two specimens of Antrodemus were unearthed. Thirty feet long, this animal was the ranking predator of its day, although hardly comparable to the towering Tyrannosaurus that entered upon the earthly scene at a later age.

Stegosaurus remains—so abundant that Douglass grew tired of them—added a bizarre note. An armored form, it was equipped with a frill of bony plates that extended the length of the back and terminated in a pair of sharp spines. Its chief claim to fame rests in its supposed two sets of "brains," one a motor-control center situated in the hip region, and the other in the usual place.

Everywhere they dug, the excavators found fresh material—a vast jumble of bones so concentrated and intermingled as to make it difficult to distinguish one specimen from another. Douglass was amazed. Obviously, it was no. with animals of a single area that he was dealing, but of an entire region. He was dealing with a dinosaur fauna. He was also perplexed. How did so many different types happen to occur in one small locality?

Slowly, as Douglass's acquaintance with the deposit grew, the answer came. It was, he reasoned, the work of a river. The sandstones were ancient sediments. In their structure and composition lay the story of swift swirling currents. The course granular texture told of fast water; the crossbedding, of shifting channels; the grouping of the bones into clusters, of eddies.

It all added up to an old delta deposit at the mouth of a river, a region of bars where the carcasses of dinosaurs brought downstream accumulated. Settling, the great hulks became buried as they sank into the receptive sand. A number of carcasses multiplied . . . and slowly, as flesh and ligament decayed, the bones became mingled, eventually to petrify and remain preserved through the ages.



At the quarry, excavating continued summer and winter. The methods employed were those that paleontologists had used for decades. There was no compressed air, no labor-saving devices. The work was done by hand. The crew, which seldom exceeded four men at any one time, became veterans in the art of fossil extraction. The bone was brittle; the encasing sandstone, hard. It required toil, patient direction, and a knowledge of anatomy.

Judiciously placed charges of giant powder shattered the overburden. Hand drills, wedge-and-feather, and crowbar worked the rock away, until the bone layer was encountered. The slow attrition by hammer and chisel accomplished the final delicate separation of the remains from the enclosing matrix. Team-and-scraper and small handcarts removed the rubble that swiftly accumulated in the cut. As the bones were chiseled from the quarry face in large blocks of rock, they were encased in strips of burlap dipped in flour paste. (Later, plaster of Paris supplanted the flour paste.) Then they were lowered by rope onto a mule-drawn skid and "snaked" down the trail into the gulch to await boxing.


Transporting the fossils from quarry to railhead was a major undertaking. It required wagon trains—4-horse teams hauling high-wheeled freight wagons over 60 miles of rutted roads to Dragon, Utah. There the precious goods were loaded onto boxcars of the now abandoned narrow gauge Uintah Railway, later to be transhipped to the standard gauge Denver & Rio Grande line at Mack, Colo.


Specimens continued to show in record abundance, most of them duplicating the earlier finds of Diplodocus and Stegosaurus. But there were new forms, too. One of them was a Camptosaurus, the first to be found at the quarry. It was a modified biped of plant-eating habits, a little more than 10 feet long, with its skull and part of the tail missing.

By 1921 the deposit had been worked to a length of 400 feet east and west, and to a depth of about 60 feet. Rock was being stripped from the quarry face at the rate of approximately 20,000 cubic feet annually, and the chisels of Douglass and his men had penetrated to the richest bone-bearing zone.

In the following year they uncovered one of the most perfect skeletons of a dinosaur ever exhumed. It was a small sauropod named, Camarasaurus lentus. When found, its 17-foot vertebral column was practically intact, except for a few tail segments. The skull was in place, and the limbs in their approximate positions.

It was an important find scientifically. The position of the limbs gave clear evidence of the manner in which these animals carried themselves. The articulation between the thigh bone and the pelvis showed conclusively that sauropods walked with their legs more-or-less vertical to the body and not with the bowed-out crawling posture habitual to lizards, as many scientists had supposed. The skull was the finest known for this genus. It was complete even to the sclerotic ring—a complex of bony plates which surrounded the living eye and protected it.

As exhibit material it was without rival. It was mounted as found, lying on its side, the bones fixed in death in the matrix in which they had been preserved—a fitting climax to the 13 consecutive years that had seen an unknown sandstone ridge in Utah become Dinosaur National Monument.

In those 13 years the Carnegie Museum had taken from the quarry parts of 300 dinosaur specimens, 2 dozen of which were mountable skeletons. Ten different species were represented. It was the best collection of Middle Mesozoic monsters in the world.

In the years that immediately followed, the still-rich "dig" was worked by two other organizations—the Smithsonian Institution and the University of Utah.

Camarasaurus SKELETON—THE MOST PERFECT REMOVED FROM THE QUARRY. (Courtesy, Carnegie Museum.)

But finally the museums had reaped their harvest. The fruits of the harvest had gone to enrich many of their finest displays. However, still buried in the untouched part of the wall were the remains of still more dinosaurs. All that was needed was to reveal them. The 67° tilt of the rock made it a perfect exhibit face. Strip off the overlying layers, expose the skeletons, and relief them in place. This had been Douglass's idea as far back as 1915, when he recorded it in his diary.


But Douglass was not the only one to realize the necessity of preserving this unique fossil record of the dinosaurs for people of today and the future to see on the spot. Officials of the Carnegie Museum realized the extraordinary nature of the deposits and their contribution to our knowledge of the past; and they were not long in taking steps to protect the dinosaur quarry. To preserve it for science, they sought to lay claim to it as a mineral property. But their claim was disallowed by the U. S. Department of the Interior, because fossil bones could not be classed as a mineral within the meaning of the mining laws.

The museum pressed its case, this time with results—but not what they expected. The outcome was not the establishment of a mere mineral claim, but of a national monument. Under the provisions of the Antiquities Act, to safeguard and preserve objects and areas of significant scientific or historic interest, the dinosaur quarry and 80 acres of surrounding land were declared a national monument on October 4, 1915. Less than a year later it was included in the newly created National Park System.

Several things contributed notably to this action to protect the quarry. They were: the exceptional preservation of the bones; the number, variety and completeness of the skeletons; the relative abundance of skulls, consisting of 8 or more in a complete state, and about an equal number of incomplete ones; and the finding of the first complete tails.

In 1923, knowing that the quarry was protected, and that the scientific collection of the fossil bones for museum exhibit was at an end, Earl Douglass turned again to the idea of making a perfected exhibit of the fossils right where they lie. His letter to Dr. Walcott, secretary of the Smithsonian Institution, reads, in part, "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."


This is precisely what the Government had in mind, and through the agency of the National Park Service, intended to accomplish. Plans for an in-place exhibit were drawn up. But many years were to elapse before the plans passed from blueprint into reality.

In the meantime, the quarry entered the second phase of its existence, a dormant period from a scientific viewpoint, but one in which the forces of the future gathered ground.

During the 1930's the monument served as a transient camp. A. C. Boyle was installed as resident geologist and custodian for the Park Service. Under his guidance a program for the general development of the area was carried on, financed largely by WPA funds. This entailed, among other things, the deepening and widening of the quarry cut, and the construction of buildings later to accommodate the monument staff and exhibits.

The American Museum of Natural History became interested in the development at this time and, through its curator of fossil reptiles, Barnum Brown, sought to initiate a joint effort with the Park Service for exhibiting the quarry remains.


It was not until September 1953 that the years of Park Service planning bore fruit, and the work of developing an in-place exhibit for the monument was begun. Many factors operated to spring the project into being, not the least of which was the active interest and wholehearted support of Horace M. Albright, a former Director of the Service.

Theodore E. White, formerly with the Smithsonian Institution and with Harvard University, was placed in immediate charge, under the supervision of Jess H. Lombard, the superintendent of the National Monument. His task, and that of his associates, was to expose the remaining specimens in the quarry wall and work them out in bas-relief.

A shelter had been built over the working space and power tools were introduced for the first time. Using compressed air, the rock was scaled off with jackhammers and "paving-breakers," until most of the overburden had been removed. Subsequent probing into the bone layer was done with smaller chipping hammers, mallet, and chisel. This operation continued through 1954 and 1955 as, slowly and carefully, the extent of the skeletal material was determined. It comprised parts of several large dinosaurs, sufficient in quantity to justify the next step—the construction of a building to enclose the quarry face.

Erection of this unusual structure, the first of its design to be attempted, commenced in 1957 and it was opened to the public in the following year. Now, as one of the many development projects in its MISSION 66 program, the National Park Service has resumed the delicate work of uncovering this corner of the ancient world and preserving it in-place for all time.

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Last Modified: Mon, Jan 17 2005 10:00:00 am PDT

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