The clockwise (southern) terminus of SR 73 is located at a junction with US 60 southwest of Show Low.

From this intersection, the highway heads southeast within the Fort Apache Indian Reservation.

It continues north through the Fort Apache Indian Reservation until it reaches its counterclockwise (northern) terminus at a junction with SR 260 east of McNary.

[2][3] SR 73 was designated on September 9, 1927 as one of the original state routes, running from US 180 in San Carlos (then known as Rice) to a junction with a county road at McNary.

[5] By 1939, SR 73 had been removed between Cutter and McNary, after being bypassed and replaced by the newly completed US 60 between Springerville and Globe, via Show Low.