Fishlake National Forest

Salina Canyon

The geologic history of the Salina Canyon area probably sounds more like science fiction than true science. And maybe it should start out: "Long ago and far away." For what is now a high desert more than a thousand miles from the ocean was once a humid coastal swamp at the edge of the sea. Where deer, elk, and cougar now roam, dinosaurs once thundered. Where Salina Creek flows to the west, a mighty river once flowed to the east. All this occurred when the rocks underlying the canyon were deposited, about 65 million years ago.

Sixty-five million years ago was about the end of the period geologists call the Cretaceous. Dinosaurs were about to become extinct. Collision of continental plates on the west coast of North America had thrust up high mountains in what is now Nevada and western Utah. Rivers draining these mountains flowed to a seaway that extended from the Gulf of Mexico to the Arctic Ocean. It covered eastern Utah and much of Colorado. Oysters and the teeth of sharks and sting rays are found in the mud deposited on the floor of this sea.

The area now occupied by Salina Canyon was part of a coastal plain between the mountains and the sea. It teamed with life; was probably quite humid, hot and abounded with bugs and creepy things. Like the present day delta of the Mississippi River, the area was swampy with islands of vegetation. Sand and mud bars accumulated alongside a mighty river that emptied into the sea. Dense jungles grew and sunk into swamps so rapidly that there was not time for decomposition of the vegetation. Thick coal seams today give evidence of the tremendous volumes of organic material produced. As sea level fluctuated, beaches advanced or retreated over the future coal beds burying them. Sediment forming these beaches was delivered by the mighty rivers coming from the mountains to the east.

since that time the whole area known as the Colorado Plateau has been uplifted over a mile. This, along with the rotation of the North American continent to another location, has changed the area from a hot, humid coastal plain with abundant rainfall to the high altitude desert we see today.

Richfield Ranger District
115 East 900 North
Richfield, Utah 84701
(435) 896-9233