Black Dragon Rest Area

One of the rest areas along I-70 in the stretch that goes through the San Rafael Swell area.

For my post about this section of Interstate 70 and links to the other rest areas on it visit this page.

Black Dragon Canyon

You have climbed from the valley floor to the top of the San Rafael Reef in about eight minutes. The road is steep but the rock layers it cuts through tilt at an even greater angle. The younger overlaying rock has been eroded, so you are standing on rocks much older than those at Green River. Anticlines are odd that way. You have gained a thousand feet of elevation, but have lost 50 million years of geologic time. The canyon in front of you is cut into some of the oldest rocks you will encounter on your journey across the Swell. These sedimentary layers were deposited before the Permian extinction over 250 million years ago. The extinction is the largest, most widespread known to modern science.

Over 95 percent of all the species then living on Earth were wiped out. Behind you is the awesome underbelly of the huge “flat iron” shaped walls of the San Rafael Reef. The striking red cliffs are stained red by the presence of iron oxide. The depth of color depends on the amount of iron oxide in the
stone.

The San Rafael Swell

You are entering a spectacular but wild landscape, the San Rafael Swell. A massive, eroded anticline, the San Rafael Swell is 75 miles long and 30 miles wide. Its sandstone reefs, buttes, pinnacles, canyons, and cliffs are stunning, if a bit intimidating. This harsh land has attracted only the toughest, hardiest of people. Early river explorer, John Wesley Powell, described the region as “a land of desolation, dedicated forever to the geologist and artist, where civilization can find no resting place.” Yet ancient Indian tribes, Mormon pioneers, cowboys, outlaws, prospectors, and miners all found a place here. Exploring the Swell off I-70 can be fascinating but dangerous to the novice. Be sure you have plenty of water, food, gasoline, and a reliable map. Hiring a guide is recommended.