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
Unconstructed state routes in Arizona US 89 from Kingman to Wickenburg while the final route of US 93 was to be constructed through Wikieup. The idea was abandoned in 1937, the same year it was proposed. The proposal for US 93 to be extended past Kingman towards Phoenix was denied by the AASHO also in 1937. It wouldn't be until 1965 that US 93 would exist south of Kingman. State Route 176 was a proposed state highway in eastern central Arizona, that would have connected Benson and San Manuel before reaching State Route 77. It was designated in 1967 but was never built, and was