This abandoned railway was originally built sometime post 1895, after the Sunset route was completed across southern Arizona. From the west, this line left the Sunset route at Wellton, AZ, and headed roughly east-northeast to reach Phoenix. This line was used by Amtrak's Sunset Limited until the mid-1990s; the track itself was never upgraded beyond jointed rail.
The middle part of the line, between Roll and Arlington, was closed some time around the UP-SP merger in 1996. The route passes through some rugged, remote territory that would require a 4WD or other off-road vehicle to explore.
The tracks on either side of this abandonment are still in use. The east end still sees some local service near Phoenix; freight customers include local ranches. This portion of active trackage extends past Arlington, where a branch to the Palo Verde nuclear power plant connects. The western segment of the line serves local ranches in the area, and is also used for car storage.
Thanks to Mike Palmer for contributing information about this route.