Marble Canyon is also well known for the Navajo Bridge, where US Highway 89A crosses the Colorado River.

Although John Wesley Powell knew this when he named the canyon, he thought the polished limestone looked like marble.

Sometimes the rocks are of many colors – white, gray, pink, and purple, with saffron tints."

Exploratory holes, which were drilled in the Redwall Limestone of the canyon walls in an early phase of the abortive project, can still be seen at Mile 39.2.

[2] The uppermost walls of Marble Canyon are composed of Kaibab Limestone upon the Toroweap Formation upon Coconino Sandstone.