Interstate 25 enters the state south of Cheyenne and runs north, intersecting Interstate 80 immediately west of Cheyenne. It passes through Casper and ends at Interstate 90 near Buffalo. Interstate 80 crosses the Utah border west of Evanston and runs east through the southern third of the state, passing through Cheyenne before entering Nebraska near Pine Bluffs. Interstate 90 comes into Wyoming near Parkman and cuts through the northeastern part of the state. It serves Gillette and enters South Dakota east of Sundance.