Arizona State Route 86 to leaving the reservation. SR 86 curves towards the east as it enters Tucson. In Tucson, the highway continues east past an interchange with I-19 to 16th Avenue, which serves as its eastern terminus. SR 86 was originally designated in 1930, between Willcox and Bowie. In 1931, it was extended west to Benson and east to the New Mexico state line, effectively serving as a direct bypass to the US 80 Douglas loop. From 1927 to 1960, the remainder of the bypass between the Arizona border and Road Forks, New Mexico was served by New Mexico State Road 14. SR
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