High Quality Content by WIKIPEDIA articles! New Mexico State Highway 80 (NM 80) is 32.416-mile (52.168 km) long north–south state road in southwestern New Mexico between the Arizona state line near Rodeo and Interstate 10 at Road Forks. Lying entirely within Hidalgo County, New Mexico, it is the only section of the old U.S. Highway 80 that Interstate 10 did not supplant in New Mexico.