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 68 trucks and recreational vehicles traveling between Arizona and Las Vegas, Nevada via US 93, due to the heavy vehicle restrictions over Hoover Dam. The detour was temporary and was removed in 2010, when the new bypass was completed south of the dam . SR 68 was a 2 lane highway and had a high grade going through the Black Mountains. The highway was expanded to 4 lanes in the mid-1990s and now has a smoother ride through the mountains. Arizona State Route 68 State Route 68, also known as SR 68, is an east–west highway in northwestern Arizona running from