Colorado is a state in the western United States encompassing most of the southern Rocky Mountains as well as the northeastern portion of the Colorado Plateau and the western edge of the Great Plains. It is the 8th most extensive and 21st most populous U.S. state. Colorado is bordered by Wyoming to the north, Nebraska to the northeast, Kansas to the east, Oklahoma to the southeast, New Mexico to the south, Utah to the west, and touches Arizona to the southwest at the Four

Wyoming is a landlocked state in the western United States. The 10th largest state by area, it is also the least populous and least densely populated state in the contiguous United States. It is bordered by Montana to the north and northwest, South Dakota and Nebraska to the east, Idaho to the west, Utah to the southwest, and Colorado to the south. Wyoming's western half is mostly covered by the ranges and rangelands of the Rocky Mountains, while the eastern half of the state is high-elevation prairie called the High Plains.