It formerly went east to the New Mexico border near Lordsburg, but this eastern segment has been superseded by Interstate 10.

From this intersection, the highway heads southeast, but curves towards the east as it enters the Papago Indian Reservation.

In Tucson, the highway continues east past an interchange with I-19 to 16th Avenue, which serves as its eastern terminus.

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.

[6] SR 86 was further extended through Tucson and the Tohono O'odham Indian Reservation to Ajo in 1943.