The Grand Canyon of the Yellowstone is 20 miles long and 1,500 to
4,000 feet wide, with a depth of 800 to 1,200 feet. The canyon is
young -- about 10,000 to 14,000 years old. The canyon was formed
by erosion rather than glaciation, and the "ooh-ahh" factor is there:
it is definitely grand and beautiful.
The Lower and Upper Falls are erosional features formed by the Yellowstone
River as it flows over progressively softer, less resistant rock.
The Upper Falls is 109 ft. high and the Lower Falls is 308 feet high.
The Lower Falls is often described as being more than twice the size of
Niagara, although this refers to its height and not the volume of water
flowing over it.
The Yellowstone River created the canyon and the falls. It
begins south of the park and travels more than 600 miles to its terminus
in North Dakota. It is the longest undammed river in the continental
US.
photo
by Kay Claybar