How long is the Grand Canyon? November 26, 2011 by Pamela Landy · Filed Under: Geography The Grand Canyon, which is the gorge of the Colorado River is 217 miles long. Fifty-six miles lie within Grand Canyon National Park in Arizona. The canyon varies in width from 4 to 18 miles. Related PostsWho was the first golfer to win the prestigious grand slam?Who was the first man to win the tennis grand slam in the same calendar year?How long was Huey Long governor of Louisiana?How long did the Pony Express last?For how long were there stockyards in Chicago?