 | This article relies largely or entirely on a single source .(July 2016) |
Prospect Dam is a former lava dam in the Grand Canyon of Arizona, United States. It was the oldest and tallest of several former lava dams in the Grand Canyon. [1] It was formed about 1.2 million years ago as lava flowed down the walls of the Grand Canyon, and temporarily stopped the flow of the Colorado River. [2]