U.S. Route 66 in Arizona U.S. Route 66 in Arizona U.S. Route 66 (US 66, Route 66) covered as part of a former United States Numbered Highway in the state of Arizona. The highway ran from west to east, starting in Needles, California, through Kingman and Seligman to the New Mexico state line as part of the historic US 66 from Santa Monica, California, to Chicago, Illinois. The highway was decommissioned in 1985, although portions remain as State Route 66 (SR 66). In 1914 the road was designated National Old Trails Highway; in 1926 it was re-designated US 66 with the birth of the U.S.
Interstate 10 in Arizona were laid out along railroad tracks, and US 60/US 70 was routed mostly parallel to the Santa Fe rail tracks east of Wickenburg, and the Arizona and California Railway west to Vicksburg. The two old federal routes then struck west across the desert and state line, picking up the Southern Pacific mainline at Indio, California, and I-10 overlies the old roads most of that distance. Moving east from the California line at Ehrenburg, I-10 follows the old route of US 60/US 70 for the first east from Blythe, California. In 1960, this western-most stretch of I-10 was built from near