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
Arizona State Route 75 with US 666 was transferred to US 666. Arizona State Route 75 State Route 75 (or SR 75) is a state highway in eastern Arizona that stretches from its junction with U.S. Route 191 and State Route 78 near Greenlee County Airport south to its junction with U.S. Route 70 in Duncan. It is primarily a shortcut for north and southbound traffic between Duncan and Clifton. The southern terminus of SR 75 is located at a junction with US 70 in Duncan. It initially heads northeast from this intersection but curves back towards the northwest. As it continues towards the