Monument Valley is located on the southern border of Utah with northern Arizona.
The valley lies within the range of the Navajo Nation Reservation, and is accessible from U.S. Highway 163.
The area is part of the Colorado Plateau. The floor is largely Cutler Red siltstone or its sand deposited by the meandering rivers that carved the valley. The valley's vivid red color comes from iron oxide exposed in the weathered siltstone. The darker, blue-gray rocks in the valley get their color from manganese oxide.