- “The next leg of our journey will take us right along the rim of the spectacular Grand Canyon. It's a long drop to the canyon floor, so please stay seated with your hands inside the train. And no smoking or flash pictures - we don't want to scare any animals. And now the Grand Canyon!”
- ―Announcer in the California version of the attraction when boarding the Tomorrowland station (pre-2008 revamp)
Built in conjunction with the musical nature documentary film Grand Canyon, the diorama is a 306 foot long display, the world's longest diorama, of environments and animals along the South Rim of the Canyon, set to Ferde Grofé’s "Grand Canyon Suite". Additionally, the Disneyland Railroad's sponsor at the time, the Santa Fe Railroad, operated passenger trains to the Grand Canyon and the diorama served as a means of cross-promoting this.
At Disneyland, the Diorama is located between the Tomorrowland and Main Street station and precedes the Primeval World, which the Railroad narrator bills as being the Grand Canyon of ancient times. At Disneyland Paris, the Grand Canyon comes before arriving at the Frontierland station, being placed behind Phantom Manor's show building.
Moving past the diorama from right to left, the attraction begins with a vista view adjacent to ancient Indian ruins and proceeds through the quaking aspens and pine trees encountering herds of deer, a mountain lion den, porcupines, wild turkeys, a thunderstorm, and concluding on a sunset over the canyon with rainbows and bighorn sheep.