DINOSAUR  NATIONAL  MONUMENT

AUGUST  2003

Dinosaur National Monument straddles the border between Utah and Colorado about 175 miles east of Salt Lake City.  The Utah portion contains the rock quarry with the dinosaur fossils for which the park is famous.  The Colorado portion lacks the fossils but has a road across the plateau to the junction of the Green River with its tributary, the Yampa River, at famous Steamboat Rock.  This picture was taken near the start of that road in Colorado looking westward toward the Utah area with its dinosaur quarry.  Most of the articulated fossil dinosaur skeletons exhibited in major museums across the United States since the early 1900's came from this quarry. 


UTAH:  THE  DINOSAUR  QUARRY             

In the latter decades of the twentieth century, it was decided to erect a building against the face of the rock wall holding the remaining fossils and display to visitors many of the remaining bones.  The fossils have been only partially excavated and are still attached to the rock face.  The picture at the right shows the present exhibit building from the parking lot.  Visitors typically walk up the ramp over the Stegosaurus to enter the building on the upper level.  The picture to the left shows a closer view of the Stegosaurus sculpture that dominates the entrance to the building. 



An overview of the upper gallery is shown to the right.  Some artwork along the gallery, shown in the picture on the left, assumes that the hides of dinosaurs probably had camouflage patterns something like those on mammals in modern African habitats similar to that which existed here at the time these dinosaurs lived.  The environment here as it may have looked as the dinosaurs were dying and being buried in the mud of the river is shown in the artwork pictured to the right.


After viewing the wall from the upper level and the art work along the walkway, visitors can descend to the lower level for a hands-on (but no climbing!) inspection of the wall, as shown to the left, and for more exhibits along the corridor.  Visitors can then exit through the bookstore/gift shop into the parking lot and catch a shuttle bus back to their car in the lower parking lot (driving up to this upper parking lot is only allowed in the early morning and in the evening when the museum is open but the shuttles are  not running).



At several places along both upper and lower galleries, there are graphic illustrations of what bones from which species of dinosaur can be seen on the face of the quarry nearby, such as the illustration on the left. It identifies hind limb bones of Camarasaurus. The matching bones on the rock wall are shown in the picture to the right.  The skull and neck vertebra of the Camarasaurus, shown slightly above and to the right of the hind limb in the graphic illustration, are pictured to the left as seen on the rock wall.  The artistic reconstruction below and to the right is what the head may have looked like in life.


A number of fossils which have been removed from the rock wall are displayed along the lower gallery.  Especially imposing is this articulated fossil hind leg of one of the larger dinosaurs.  The red color of the backdrop for it is an illustration of the muscles that would have covered it.  Note the visitors in the background for scale!  The skulls in the picture below are among the other displays along the lower gallery.  A child was comparing his hand with the fossil bones of the forefoot of an Allosaurus.








Remember the Stegosaurus whose sculpture guards the entrance to this marvelous fossil site?  Here is a plastic model of that beast with some bones found at this site inserted where they would have been in the living beast.  Some of the plates of the Stegosaurus have also been found here, and a few can be seen on the quarry wall (pictured at right).  None have ever been found articulated with the skeleton though, so it is not really known how they were arranged on the body.  The arrangement typically seen in drawings like the one at the left, with them sticking up along the spine, is just a guess, and other guesses have also been made.  At least some fossilized dinosaur skin has been found at this quarry, proving that at least some of the dinosaur species had skin or hide rather than scales, feathers, or fur.  One such fossil is displayed in the lower gallery.  Perhaps finds yet to be made, if not here then elsewhere, will eventually resolve the question of the actual location of those Stegosaurus plates on the critter's body!


COLORADO: JUNCTION OF THE GREEN AND YAMPA RIVERS AT STEAMBOAT ROCK

The road into the plateau country of the Colorado part of Dinosaur National Monument passes a number of spectacular viewpoints looking onto the canyons eroded into the plateaus by the Green and Yampa Rivers.  These rivers, like the Colorado River, apparently meandered across a low-lying plain and cut their winding courses downward as the land gradually rose to its present altitude above sea level.  One of those scenic views is shown on the right, looking toward the canyon of the Yampa River.  The Yampa is a major tributary of the Green River, which is itself a major tributary to the Colorado River, joining it in Canyonlands National Park, farther south in Utah, just above Lake Powell and Glenn Canyon Dam.  A telephoto view on the left taken from the same viewpoint shows the upper part of famous Steamboat Rock.  The Green and Yampa Rivers meet just about in the middle of the picture, just out of sight beyond the rock.

At the end of the road, a hiking trail goes out on a promontory around which the Green River winds immediately after it is joined by the Yampa.  The remaining pictures were all taken from that hiking trail.  The next two pictures show the setting of Steamboat Rock.  A nearly flat portion of the plateau ends abruptly in the upper left of each picture at the canyon of the Yampa R. which is flowing toward the camara viewpoint.  It joins the Green River on the far side of the rock. 

A closer view of the river junction is shown below to the left, taken farther out on the hiking trail.  The canyon coming from the upper left is that of the Green River.  A bit of the brown river can be seen at the base of the nearly vertical canyon wall.  It comes toward the uptilted rocks at the left front of the picture.  It then flows left to right in a canyon so narrow through the rock mass in the middle of the picture that it is virtually impossible to trace just where the canyon is even with powerful binoculars.  In the middle right part of the picture, the canyon of the Yampa R. also comes toward the rock, the Yampa emptying into the Green River as the latter flows along the far side of Steamboat Rock.  The Green River then continues flowing to the right, comes around the end of the rock, and then flows from right to left across the lower part of the picture, between Steamboat Rock and the promontory ridge the hiking trail follows.  It then flows around the end of the promontory where the hiking trail ends at a flat rocky platform nearly surrounded by sheer dropoffs.  The river cuts along the edge of the ridge behind the camera position here, and makes yet another sharp turn away from the ridge.  The pictures below show the course of the Green River away from the ridge, an overview on the left and a telephoto on the right.  The Green River above the Colorado River is very popular for white water rafting tours. There is a rapids in the river at the bend before the first island in the picture on the right, and more rapids could be seen downstream with binoculars.

Dinosaur National Monument is a wonderful area to visit with its scenic beauty and its fascinating geology, not to mention the fabulous fossils testifying to its intriguing past.