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 93 being extended from Kingman by way of US 66 through Ash Fork. A new US 193 was proposed from Phoenix through Sacaton and Casa Grande to Picacho. At the time, US 89 served the road between Ash Fork and Phoenix, while State Route 87, State Route 187 and State Route 84 ran between Sacaton and Picacho through Casa Grande (of which only SR 87 still traverses today). Upon hearing of the proposed extensions, citizens of Wickenburg, Arizona, Wikieup and Aguila protested to have US 93 run through their towns instead. The protest was considered and the Arizona Highway Department changed