US 60 was one of the first east-west transcontinental highways. It was commissioned in 1926, and stretched from Virginia Beach, Virginia to Los Angeles, California. Today, its western terminus is in Quartzsite, Arizona (18 miles east of the California border), with the remainder of the route to L.A. being picked up by Interstate 10.

In central Arizona, US 60 passes through the mining town of Superior. In and around Superior, previous alignments of US 60 may be found rather easily. As technology improved (steel suspension bridges, longer tunnels, etc.), US 60 was often able to be realigned in places to do away with excessive curves and overly steep grades.