Yellowstone Falls consist of two major waterfalls on the Yellowstone River, within Yellowstone National Park, Wyoming, United States. As the Yellowstone river flows north from Yellowstone Lake it decreases in altitude and plunges first over Upper Yellowstone Falls and then a quarter mile downstream over Lower Yellowstone Falls, at which point it then enters the Grand Canyon of the Yellowstone, which is up to 1,000 feet (304 m) deep. The upper falls are 109 feet (33 m) high while the lower falls are 308 feet (94 m)high, or almost twice as high as Niagara. The volume of water is in no way comparable to Niagara as the width of the Yellowstone River before it goes over the lower falls is 70 feet (22 m), whereby Niagara is a half mile (800 m). The lower falls of the Yellowstone are still the largest volume major waterfall in the Rocky Mountains of the United States. The volume of water flowing over the falls can vary from 63,500 USgal/s (240 m³/s) at peak runoff to 5,000 USgal/s (19 m³/s) in the fall.

It is believed that Jim Bridger may have been the first white American to see the falls in 1846. The Folsom Party, a private group of explorers working in close relationship with the U.S. Government, named the falls in 1869. During the Hayden Expedition of 1870 to 1871, the falls were documented in photographs by William Henry Jackson and later in paintings by Thomas Moran.

Today, there are numerous vantage points for viewing the falls. The Canyon loop road skirts the west side of the canyon with several vehicle parking areas. One trail leads down to the brink of the lower falls, a steep third of a mile (.6 km). Another vantage point descends from the east down a series of stairs attached to the cliffs.

Lower Yellowstone Fall

Lower Falls of the Yellowstone River

Upper falls of the Yellowstone River