Dinosaur National Monument Region

Many river canyons in the Rocky Mountains cut through mountain ranges rather than flowing around their lower flanks. Observations by Powell and his crew lead to ongoing debates about whether the river system existed before or after the uplift of the mountains and plateaus [particularly Dutton's (1882) theory of the "Great Denudation" of the Rocky Mountain region and Colorado Plateau]. In mid-Tertiary time many of the ranges in the Rocky Mountain region were "buried in their own sediments" derived from erosion of mountain ranged formed during the Laramide Orogeny which began in the Late Cretaceous (about 70 million years ago). An ancient river system drained toward the midcontinent well into late Eocene time - about 40 million years ago. However, the "modern" canyons of the Green and Colorado rivers have formed since late Miocene time (roughly within the past 10 million years; Lucchitta, 2003). The region is still continuing to rise as rivers carved downward, exhuming preexisting structures of the earlier Laramide Orogeny. Observable field evidence suggests that nearly a mile (or more) thickness of rock material has been eroded from much of the region since the modern river system developed, with most erosion occurring in the Quaternary Period (over the last 2 million years).

"Fantastic Rock," foot of Browns Park, Vermillion Creek. Colorado
USGS Earth Science Photographic Archive digital file: hjk00486

The Second Expedition (1871) took more time than the First (1869) to traverse the Green River section around the Uinta Mountains and through Dinosaur National Monument, taking time to explore side canyons, collect fossils, observe wildlife and plants, and photograph. By comparison to the First Expedition, the second trip through the region was relatively uneventful. In 1869, the expedition experienced loss of one of their boats loaded with supplies, a fire that nearly destroyed their supplies, and three of their crew who had abandoned the mission near its end were killed by Indians. The also faced the daily unknown terror of rapids and falls in potentially unescapable canyons in unexplored territory.

The Tower on Vermillion Creek, Browns Park. Colorado
USGS Earth Science Photographic Archive digital files: hjk00487 and hjk0048

Vermillion Creek drains into the Green River near the eastern end of the Uinta Range. John C. Fremont's expedition passed eastward through the Vermillion Valley in route to the mountain "park" valleys of Colorado in 1842.

A rapid in the Canyon of Lodore, Green River. Dinosaur National Monument. Moffat County, Colorado.
USGS Earth Science Photographic Archive digital file: hjk00502

The washed-out character of this image shows the difficulty of getting the right exposure. Experience and a trained eye were necessary for getting the right lighting of landscape features balanced with the right photographic exposure and processing.

Canyon of Lodore, Green River. Dinosaur National Monument. Moffat County, Colorado. June 1871.
USGS Earth Science Photographic Archive digital file: hjk00503

Note about anaglyphic images: the red color is associated with the left image, the cyan color is associated with the right. In this case the "left" side of plate was broken, causing the cyan to stand out where part of the plate is missing (both images were typically burned onto a single plate negative in the camera equipped with dual lenses). When red and cyan are combined in the images, the result is a gray-scale palette (white to black). The aged original photographs also had brownish tones that come through in many of the images. Unusual shaped patches of red or cyan color are usually imperfections in the original negative plates, either scratches or where the coating may of rubbed off or were perfectly prepared before exposure. Considering the time constrains, methods involved, and circumstances required to take and transport the glass plates, cameras, and photographs supplies, the survival of so many scenes is a reflection of the remarkable dedication to the photographic aspects of the expedition.

Disaster Falls in Canyon of Lodore, Green River. Dinosaur National Monument. Moffat County, Colorado. June 18, 1871. Photo by E. O. Beaman.
USGS Earth Science Photographic Archive digital file: hjk00577

In 1869, the First Expedition's loss of one of three boats (the "No Name") at Disaster Falls on June 7th, 1869. One whole boatload of rations, equipment, and the boat crew's guns and clothing were lost, although some of the instruments and rations were later salvaged. A three-gallon keg of whiskey smuggled onto the boat without Powell's knowledge was also recovered, which Powell shared, at first reluctantly, with his men to rebuild morale. It would take them several days to portage the rapids and to dry out their rations. Shortly afterward, a camp fire burned out of control and caused additional damage and alarm. However, despite their losses (no one was seriously injured), the voyage continued into what Powell described as some of the most spectacular scenery of the journey. With success in hunting and fishing, their spirits soon recovered. In 1871, the crew of the Second Expedition found remnants of the No Name along the river two miles below the rapids where it had been lost.

Canyon of Lodore, Green River. Dinosaur National Monument. Moffat County, Colorado. 1871.
USGS Earth Science Photographic Archive digital file: hjk00593

Angel's Whisper, a side canyon of Lodore Canyon. Dinosaur National Monument. Moffat County, Colorado. June 1871.
USGS Earth Science Photographic Archive digital file: hjk00630

The original caption for this stereo photograph was incorrect. It was originally "Canyon of Lodore, near lower end" Green River... Moffat County, Colorado. June 27, 1871. (USGS Earth Science Photographic Archive digital file: hjk00649).

Bruce R. Julian (USGS), however, has identified the location as Warm Springs rapid on the Yampa River. Hillers and others did go on frequent scouting mission throughout the voyage. Bruce wrote:

"This picture is particularly important because it was the site of a major (~1000 year) flash flood/debris flow on June 10, 1965. I know because I was there, and was nearly killed. (The next day a professional boatman WAS killed by the rapid.)"

Rock pinnacles in Split Mountain Canyon, Green River. Dinosaur National Monument. Uintah County, Utah. July 1871.
USGS Earth Science Photographic Archive digital file: hjk00700

Cliffs of Weber Sandstone (Pennsylvanian and Permian age) form the canyon rim throughout the Split Mountain.

Split Mountain. Dinosaur National Monument. Uintah County, Utah.
USGS Earth Science Photographic Archive digital file: hjk00674

This view looking downstream toward the lower canyon where cliffs of Weber Sandstone (Pennsylvanian and Permian age) crop out high on the mountainsides. Downstream of the lower gorge the Green River crosses through hogbacks of steeply dipping strata of Mesozoic age that crop out along the south side of the Split Mountain anticline.

Rocky gorge of Brush Creek, on Ashley Fork, Green River. Uintah County, Utah.
USGS Earth Science Photographic Archive digital file: hjk00495

On the First Expedition (1869), Powell's party camped near the mouth of Ashley Creek while the Major's boat proceeded downstream to the Uintah [Duchense] River -- the next tributary to the south where a overland route between Denver and Salt Lake City crosses the Green River. At the crossroads, Powell and his companions continued 40 miles west to the Uintah Ute Agency to collect and send mail, ship fossils, and purchase more food for the journey. The remaining men trailed behind hunting, fishing, and exploring the river valley, waiting for the Major's return near the confluence of the Duchense and Green Rivers. They reported having had a miserable experience dealing with mosquitoes waiting for Powell's return a week later. They then departed downstream into uncharted territory along the Green River: the Desolation Canyon wilderness.

On the Second Expedition (1871) Powell left at Ashley Creek to be with his child-bearing wife, Emma, in Salt Lake City and to troubleshoot problems for the rest of the journey. Powell turned the command over to his brother-in-law "Prof" Almon Harris "Harry" Thompson to lead the expedition downstream. Powell rejoined the Second Expedition in at "Gunnison Crossing" (Green River, Utah) on September 3rd.

Click here to continue to the "Desolation Canyon" page.

Click here to see recent photography of Dinosaur National Monument.