Sandstone “Pillows” Below The San Rafael Reef, Utah

Pillows of Dakota Sandstone provide an interesting foreground detail in this photograph of the San Rafael Reef in south/central Utah. The jagged front of the San Rafael Reef is identical to many other monoclines on the Colorado Plateau. It was created by an underground fault which did not break the surface during the Laramide Orogeny which created the Rocky Mountains to the east of here beginning about 60 million years ago. This fault slowly shoved an 80-mile long block of crust into the sky to form the San Rafael Swell. The fault was located deep under the eastern edge of this bulge thus deforming the earths crust most dramatically at this location. The name reef was applied to these jagged sandstone outcrops by early explores due to their tendency to impede travel.