The Navajo Formation, over 1,400 feet (427 m) thick in places, caps the upper reaches of Capitol Gorge. Its white, rounded domes, reminiscent of the nation's capitol building, inspired part of the name for Capitol Reef. Prospectors with seafaring experience viewed this monocline as a barrier to transportation, and supplied the nautical term "reef".
Wingate and Navajo, both formed from ancient deserts, seem to erode differently. The Wingate tends to make sheer cliffs; the Navajo rounded domes.
The Wingate lies on soft beds of Chinle Formation. Because this softer rock erodes more rapidly and undercuts the Wingate, the massive sandstone often breaks away to form sheer cliffs. By contrast, the Navajo rests on a firm foundation of a Kayenta.
The Navajo is undercut less often than the Wingate and erodes away in smoother contours. The Kayenta lies above the Wingate and below the Navajo Formation. It is about 350 feet (107 m) thick and 190 million years old.