Ashley National Forest: The High Uintas and the Dinosaur Country Below

Ashley National Forest covers the northeastern corner of Utah and a slice of Wyoming, roughly one million three hundred thousand acres of the Uinta Mountains and the Uinta Basin below them. The forest is named for William Henry Ashley, the fur trader and Missouri congressman who organized some of the earliest systematic trapping expeditions into the Green River basin in the eighteen twenties, opening the Rocky Mountain fur trade to large-scale commercial operation. Ashley's men included Jedediah Smith, Jim Bridger, and Thomas Fitzpatrick, names that appear throughout the early history of the American West as cartographers of territory they were simultaneously depleting.

The Green River runs through the eastern edge of the forest and continues south through Dinosaur National Monument, where the quarry wall of exposed Jurassic bone, discovered in nineteen nine and excavated over the following decades, contains one of the densest concentrations of dinosaur fossils ever found. The Morrison Formation that holds the fossils was deposited during the late Jurassic period, approximately one hundred and fifty million years ago, when this part of North America was a subtropical floodplain. The forest sits on top of it.

At the northern end of Ashley National Forest, the High Uintas push above twelve thousand feet, a landscape of glacially scoured basins and alpine lakes with almost no tree cover above treeline. The Wind River Range in Wyoming is visible to the north on clear days. John Wesley Powell launched his eighteen sixty-nine Colorado River expedition from Green River Station, roughly forty miles east of the forest's eastern boundary, into a landscape the forest now partly administers.