At the Dry Falls overlook in central Washington, the first thing you notice is the quiet. The cliff in front of you is about three and a half miles wide and about four hundred feet tall. It has the shape of a waterfall, a horseshoe lip worn smooth, and at the bottom there are lakes. From the rim they look like ponds. They are the plunge pools. Water once fell onto those spots hard enough to dig them out of solid basalt. Then it stopped falling, and the holes filled with rain.

Niagara is roughly a mile wide and 170 feet tall. Dry Falls is several times wider and more than twice as tall. How many times bigger depends on what you measure. Either way, no water has gone over it in about fifteen thousand years.

It was made by the Ice Age Missoula Floods. We covered those in an earlier film, so this one stays with the place: the columnar basalt the cliff is built from, the lakes at its base, how the falls ate its way about twenty miles upstream from Soap Lake before the water ran out, and what is left when a waterfall outlives its river.

Dimensions and dates come from Washington State Parks, USGS and Washington Geological Survey work on the Channeled Scablands, and J Harlen Bretz's original papers. Flood discharge and the number of floods that reached the falls are estimates, and they're given that way.