Dry Falls, Ancient waterfall site in Grant County, United States

Dry Falls is a former waterfall site in Grant County, Washington. The semicircular rock wall stretches for several miles and rises about 400 feet (121 m) above the floor of the present dry valley.

About twenty thousand years ago, an ice sheet dammed the Clark Fork River near Sandpoint, Idaho, forming Glacial Lake Missoula. Its repeated outburst floods, joined by overflow from Glacial Lake Columbia, poured down the Grand Coulee at up to 65 mph over this 400-foot face, carving the four alcoves and plunge pools. When the ice melted, the Columbia returned to its course and the falls went dry.

The name comes from the fact that no water flows over the cliffs today, though once this site channeled one of the greatest water volumes on Earth. The area is now walked by hikers who cross the dry basalt rocks and trace the scale of the erosion that shaped the land.

A visitor center provides information about the formation of the landscape and sits directly on the main road, from which several viewpoints are accessible. Hiking trails run along the cliffs and down into the valley, where traces of erosion can be seen up close.

The rock wall shows clearly visible channels and basins carved by the flowing water into the stone. Some of these depressions are so large that entire houses could fit inside them, illustrating the force of the former flood.