Wyoming is a state in the northwestern region of the United States. It is the 10th largest in area, but the least in population. It is bordered by Montana to the North, South Dakota and Nebraska to the East, Colorado to the South, Utah to the southwest and Idaho to the West.
In the movie, it is where Yellowstone National Park is as Jackson Curtis and his family visit as well as the location of the Yellowstone Caldera. Later in the film, the Caldera erupts, completely destroying the park and the entire state as an ash cloud begins 'swallowing' most of the western United States.