Tilted Rocks Auto Tour

What's in a name? In Dinosaur National Monument, there's much more than what's in the name alone. This guide to the Tilted Rocks is a brief look at the Monument's diversity of sights and stories. Allow about 1 1/2 to 2 hours for this 22 mile round trip; this is time to drive at a leisurely pace and to get out now and then for a better view. If you have more time, there are suggestions for further walks or hikes in this area, as well as other parts of the Monument to visit.

Protect yourself and your Monument. Please drive carefully, and stop only in parking areas or where there is ample space on the shoulder. Don't drive off the road, as this scars the land and could also strand your vehicle. The route includes a 2 mile stretch of unpaved road, which may be inadvisable for travel in wet weather.

Please remember that a national monument is a home for all plants and animals, and take care while you are a guest in it. Remember too that you share this land and its resources with everyone; leave all rocks, flowers, artifacts and other objects in place just as you first see them.

For a picnic, you are welcome to use either Split Mountain or Green River Campground (the latter has more shade), or the tables near the Josie Morris Cabin at the end of the road. Drinking water is limited. Fires may be built only in the fire grates in the campgrounds.

Begin your tour from either the Dinosaur Quarry or the Summer Visitor Center, depending on where you are parked. At the first stop sign, turn left toward the campgrounds, and watch for the numbered posts on the roadside, beginning one mile from the stop sign.

(Mile and kilometers listed at each stop are cumulative.)

tour map

  1. (1.0 1.6) As you entered this corner of Dinosaur National Monument, you followed the Green River for a few miles, and you are still in its valley here. Along with its tributary the Yampa, the Green River is responsible for most of the size and shape of the Monument, which originally enclosed only the Dinosaur Quarry. In 1938 the monument was greatly enlarged - not to take in more dinosaur fossils, but to protect the deep, colorful canyons carved by these two rivers. Besides creating dramatic scenery, the rivers also make possible a greater variety of life than could otherwise exist in this high desert.

    One of the Monument's oldest known sites of human life lies just across the road. Six feet below the present floor of the "Swelter Shelter" (named by the researchers who excavated it in the heat of summer), projectile points were found that may date from as long ago as 4,000 to 7,000 BC. Little is known of their long-vanished makers, who are now called simply the Desert Culture.

    The pictographs (paintings) and petroglyphs (scratched or carved designs) on the shelter's walls are not quite so ancient. They were probably made about 1,000 years ago by the people of the Fremont Culture (named for the Fremont River in southern Utah), whose rock art appears on many cliffs and canyon walls, including more sites farther along this road. These drawings are very fragile - do not touch them.

  2. (2.3 3.7) Prairie dogs are a common sight along here, as they pose bolt-upright on their mounds or forage for leaves, seeds, and insects. (Watch out for them on the road as well as beside it.) Like many rodents, they are well-suited for desert life; they can get all or most of the water they need from their food, and they can easily cool off now and then by retreating into their burrows. Larger animals such as badgers, foxes, coyotes and mule deer also live here, but are less often seen. They conserve water and energy by staying hidden during the day, and usually come out after the sun goes down.

    Turn left on the road to Split Mountain Campground for the next three stops on the tour.

  3. (2.8 4.5) The rugged skyline ahead is the top of Split Mountain, so named because the Green River has split it in half. In so doing, the river produced a spectacular canyon, and a geological mystery: how and why did the river cut through the center of a mountain instead of taking an easier course in the lower land around it? The next two stops will look into the mountain and the mystery in more detail.

  4. (3.1 5.0) The steep tilt of the rock layers around you is what made Split Mountain a mountain. These strata were once level, but have been warped upward into an irregular dome shape. The seemingly logical course for the Green River would be around the dome, particularly in the softer rock layers that have been eroded into narrow valleys like this one. Instead, the river cuts across these valleys and through the hard sandstone in the center of the dome. Some early geologists suggested that, to be able to do this, the river must have been flowing in its present course before the upwarping occurred. Then, as the rocks began to rise, the river held its course by cutting through them, like a power saw slicing through a log pushed against it. A tidy theory, but it has a major flaw - other geological evidence shows that the Green River did not establish its course here until long after the upwarping took place.

  5. (3.4 5.5) This is a good place to get out for a better look at Split Mountain and the mouth of the river's gorge - and also the rounded rocks on the ground around you. That roundness probably came from rolling along in the river, and since the rocks certainly didn't roll up to this height, the river must have cut down from here. In fact, rocks like these are found at even higher elevations, and geologists think that they are the remains of a great blanket of sediments washed into this area from the higher Uinta Mountains to the west. These sediments buried the older upwarped rocks here, forming a nearly level plain on which the Green River developed its course. As the river began to cut downward, it struck the buried dome of Split Mountain, but by then it was held in place by its banks, and could not change course to go around the hard sandstone. Meanwhile, erosion of the surrounding area removed most of the newer, unsolidified sediments, exposing the mountain as a dome again - but now a dome split in half by the Green River.

    To continue the tour, drive down the hill, park and walk to the boatramp. There are exhibits here, and during summer afternoons you can watch river runners unpacking their boats.

    Return up the same road and turn left at the stop sign.

    For a closer look at the Split Mountain area, the Desert Voices Nature Trail, beginning across the road from the campground parking lot, is a 2 mile, moderately strenuous loop. The best time to walk this trail is early morning or late afternoon, when it is cooler, colors are brighter, and wildlife may be more active.

    For the ultimate view of the canyons, take a half-day trip up the Harpers Corner Scenic Drive, a paved road beginning at Monument Headquarters in Colorado. Roadside overlooks and a 2 mile nature trail give superb vistas of the Green and Yampa River canyons. Guide leaflets for both the road and trail are available at the Dinosaur Quarry and at Headquarters.

  6. (5.8 9.3) This overlook provides a panoramic view of the Cub Creek Valley, which lies between Split Mountain on the left and Blue Mountain on the right. Cub Creek empties into the Green River just downstream for here.

    The influence of water is easy to see here. The native cottonwood trees shading the campground below you depend on the Green River, as do the irrigated crops in the privately owned field across the river. Just a short distance away from the river, sparse grasses, shrubs such as sagebrush and greasewood, and a few small juniper trees reveal the true desert nature of this land. Here, at about 5,000 feet elevation, rain and snow provide less than 10 inches of water a year, and plants that have so little to drink must conserve water or perish. (Cacti, although they are champion water-savers, are small and scarce here because few of them can tolerate the sub-zero winter temperatures.)

  7. (6.5 10.5) Ahead and to the right, the hills are banded with shades of gray, red, purple and brown. This distinctive color pattern, which has been likened to "melting Neapolitan ice cream," helps to identify the Morrison Formation, a group of rock layers that occurs throughout this region. Paleontologists find this rock attractive for more than its colors; a few of its outcrops contain 140 million year old dinosaur fossils like those in the Monument's Quarry. The formation originated as muds and sands laid down by a network of ancient rivers, whose water nourished an abundance of plants, dinosaurs and other animals. During flood stages, the rivers sometimes collected and buried large numbers of dinosaur bones and carcasses, making the Morrison Formation a rich storehouse of fossil clues to the past.

  8. (7.2 11.6) This short side road (may be impassable in wet weather) leads to Placer Point, on a large bend of the Green River. The name refers to an effort in the 1930s to dredge and sluice gold from the river bottom here. However, the gold proved to be too powdery to extract profitably, and the operation eventually folded.

    Although gold did not play a leading role in this area's history, the Green River itself did. Its canyons made the land so rugged that explorers and settlers largely bypassed the area - except for a handful who tried floating down the river, not always successfully. In recent years though, river-running has quickly grown into a popular sport, and now thousands of people delight in the whitewater that terrified earlier boaters such as William Ashley and John Wesley Powell.

    Just beyond Placer Point, before the main road crosses the river, are exhibits about the role of fire in the desert.

  9. (7.6 12.2) For the next 2 1/2 miles, the road passes outside the monument, through land ranched by members of the Chew family, who have lived in this region since the turn of the century. Here the Chew's raise alfalfa, corn, and other crops, as well as sheep and cattle (which graze on higher rangeland to the east during the summer).

  10. (9.4 15.1) From long-time settlers to brief passers-by, many of us like to name what we see around us. The rock on the left has gone by many names, depending on who was looking at it and how far they let their imagination go. What would you call it?

    "Turtle Rock" is the name most often suggested, but "Skull Rock" runs a close second. The many holes result from more rapid weathering of the weaker parts of the rock. This is Entrada Sandstone, the same type of stone which forms the arches in Arches National Park. Arches develop when such holes eventually penetrate the thin walls of the rock, but this outcrop is fairly thick - so you'll probably have to wait a few million years to see an arch here.

  11. (10.0 16.1) This tour continues to the left here. The road on the right leaves the Monument; it is steep, rough and suitable only for 4-wheel drive vehicles.

    The left fork crosses Cub Creek, a spring fed stream that runs all year. Its channel may seem deep for such a small volume of water, but the creek is not always small. Occasional cloud bursts can swell it to a muddy, roaring torrent, and it is then that the creek erodes its banks most rapidly - and sometimes cuts right through the road as well.

    (10.3 16.6) Elephant Toes Butte, across the creek, is eroded from the Glen Canyon Sandstone, which dates from the Age of the Dinosaurs but records a far different environment from that of the Morrison Formation. The type of layering found in this rock shows that it originated as sand dunes in a windswept desert. Dinosaurs could not have lived here then - but that hasn't prevented the use of "Brontosaurus Toes" as an alternate name for this landmark!

  12. (10.6 17.1) Please remember not to touch this rock art, and, for your own safety, watch your step if you walk up for a closer look.

    Like those at Swelter Shelter, these drawings were probably made by the Fremont people about 1,000 years ago. Using sharp tools, they pecked away the dark desert varnish," a natural stain on the rock surface, to reveal the light-colored sandstone beneath. Many of the designs, such as bighorn sheep and other animals, are easily recognizable, but their meaning is not. Was this religious art, or a written language, or just something to fill idle moments? No one knows.

    One thing that the petroglyphs do tell us is that their makers did not have to spend all of their time struggling to survive. With the reliable water supply of Cub Creek, they could settle in small village groups and grow crops to supplement the foods the hunted and gathered. They could take the time to create artwork that, whatever its purpose, would endure long after they were gone.

  13. (10.8 17.4) On the rock ledge high above the left side of the road, look for the darkest patches of desert varnish. Can you find at least two large lizard drawings? If you have binoculars, you may find many smaller petroglyphs as well.

    Three-tenths of a mile farther, watch for the last group of petroglyphs on this road, on a low rock face on the left. Sometimes called the "three princesses," the figures have the trapezoidal bodies, necklaces, and headdresses that are typical of Fremont representations of humans - but again, their true meaning remains a mystery to us.

  14. (11.7 18.8) In 1914, a year before the Dinosaur Quarry was designated as Dinosaur National Monument, a woman named Josephine Bassett Morris began a home here. Josie had spent most of her first 40 years in Brown's Park (just north of the present Monument area); she would spend most of the next 50 at Cub Creek. She had been married several times, but here she lived alone except when family or friends visited.

    Josie's homestead was about 1 mile by 1/2 mile, and on it she raised livestock, field crops, vegetables, and fruits - without motor vehicles, electricity, or other "modern conveniences." After her death in 1964, her land became part of Dinosaur National Monument, preserving a spot where the "old West" isn't so old at all.

    The steep mass of Split Mountain forms a backdrop to Josie's home. This rock is Weber Sandstone, another ancient dune formation, in this case, even older than dinosaurs. Erosion has cut deeply into the rock in places, forming narrow canyons with nearly vertical walls. Josie used two of these box canyons - the one by the parking area and the next one to the east - as corrals. She simply fenced the narrow open ends, and let the canyon walls confine her stock. The canyons also provided most of Josie's water supply, channeling the runoff from rains and releasing groundwater in the form of springs.

    A short walk would make a pleasant conclusion to your journey before you return over the same road. You can stroll right into the first box canyon from the parking area, or you can follow the path past the canyon and other buildings for about half a mile into Hog Canyon. The canyon floors offer fairly level, easy walking, and have shade even at midday. Please note: you should not try scrambling up the cliffs and canyon walls, which are hazardous due to their steepness, loose rocks, and sudden drop-offs.

For a good one-day hike in a similar green and shady setting, try Jones Hole. A fairly easy trail follows Jones Hole Creek for 4 miles through a deep gorge, leading to the banks of the Green River in Whirlpool Canyon - one of the few inner-canyon areas accessible by land. Ask at the Dinosaur Quarry for road directions and a map.
Text by the Interpretative staff of Dinosaur National Monument. Artwork by Adrienne Burks.

Published in cooperation with the National Park Service, U.S. Department of the Interior, for the benefit of visitors to Dinosaur National Monument, Utah-Colorado.

© 1993 Dinosaur Nature Association
1291 E. Highway 40,
Vernal, UT 84078

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© 1995 Karen M. Strom