Yellowstone Caldera Chronicles is a weekly column written by scientists and collaborators of the Yellowstone Volcano Observatory. This week’s contribution is from Michael Poland, geophysicist with the U.S. Geological Survey and scientist-in-charge of the Yellowstone Volcano Observatory.
The Lower Falls of the Yellowstone River and the Grand Canyon of the Yellowstone were photographed during a helicopter flyover on August 19, 2019.
Michel Poland, USGS
The Grand Canyon of the Yellowstone is a natural wonder that almost defies description. The reaction of explorer Charles Cook when he first viewed the canyon in 1869 seems appropriate: “I sat there in amazement, while my companions came up, and after that, it seemed to me that it was five minutes before anyone spoke.”
Stretching from the Lower Falls to the Tower Falls area, the Grand Canyon of the Yellowstone is about 28 kilometers (17 miles) long, 250–350 meters (820–1,150 feet) deep, and 450–1,200 meters (1,500–4,000 feet) across. It appears to be a surprisingly young feature of the region, having mostly formed during and immediately following the last ice age, within the past 20,000 years or so.