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
U.S. Route 80 in Arizona was bypassed in 1956 to cross the Colorado River, while the later alignment continued straight ahead into California. Upon crossing the Colorado River to the Fort Yuma Indian Reservation, the older route was still in Arizona. Unlike most of the California and Arizona state border which resides along the Colorado River, the border temporarily cuts north here through the Reservation then east back to the Colorado. This places several acres of land on the western side of the river in Arizona. For a few hundred feet, the state border runs along the western shoulder of pre-1956 US 80. A short