State Route 78 (Arizona–New Mexico) State Route 78 (Arizona–New Mexico) Arizona State Route 78 (SR 78) and New Mexico State Road 78 (NM 78) are a pair of adjoining state highways located in eastern Arizona and western New Mexico linking U.S. Route 191 (US 191) and Arizona State Route 75 near Greenlee County Airport to US 180 northwest of Cliff, New Mexico. It is also known in its Arizona stretch as Mule Creek Road. The western terminus of SR 78 is located at a junction with US 191 and SR 75 at Three Way, Arizona near Greenlee County Airport. The highway heads northeast from this
U.S. Route 80 in Arizona road side businesses and attractions, including many iconic motor hotels and restaurants. US 80 was a particularly long highway, reaching a length of almost within the state of Arizona alone. With the advent of the Interstate Highway System, Interstate 10 and Interstate 8 both replaced US 80 within the state. US 80 was removed from Arizona in 1989; the remainder of it now being State Route 80. In September 2018, the Arizona Department of Transportation designated former segments of the highway as Historic U.S. Route 80. On its journey across Arizona, US 80 made two indirect loops to both Phoenix