Seem to recall the route is signaled to Wellton. Saw a picture of a stop signal at the end of active track.
This Phoenix Line discussion is about to turn into a subject of its own.
I found a piece of a 2004 UP Employee Timetable for this area. Follows is some information from it:
The lines are mileposted from West to East. Milepost for passenger stations are not given. I have put in my best guess and labeled them as such. Here they are, beginning at Yuma and going east. Appears that the milepost for Yuma may be the passenger station.
732.7 Yuma
770.7 shown as beginning milepost of Phoenix Line
770.8 Wellton With reduction of 0.6 miles due to milepost equations, 37.5 miles
896.0 Maricopa west end siding. With reduction of 0.4 miles due to MP equations, 124.8 miles fm Wellton
897.7 Maricopa east end siding. Station likely in this distance somewhere
936.7 Picacho west end siding - junction somewhere in this siding?? 39.0 miles between adjacent siding ends
938.4 Picacho east end siding
984.5 Tucson Station - approximate. Yard milepost 986.6
987.7 Gila Subdivision / Lordsburg Subdivision transition
1296.0 El Paso "Civic Center" Maybe Station Location? With reduction of 2.4 miles due to MP equations, 309.1 miles between stations Tucson to El Paso.
Speed limits are 79 passenger, 65 freight, 70 expedited freight, but with many speed restrictions of 70 mph to 55 mph, with a few less.
Now for the Phoenix Line:
770.7 Wellton - beginning portion shown designated as Roll Industrial Lead - ABS in service, but 20 mph, disregard signals.
771.0 derail
777.0 derail
782.3 end of in-service track - begin out of service track, next 20.5 miles out of service
802.8 end of Roll Lead, begin Phoenix Line Main Track - next 51.2 miles out of service. Total 70.7 miles OOS
854.0 begin in-service track - 25 mph speed limit (unless reduced by slow orders which is likely.)
904.8 end 25 mph limit, begin 20 mph limit.
906.0 Phoenix Station - maybe - in 15 mph speed limit section.
907.0 Phoenix Yard
924.2 End low speed section with speed limits of 20 mph to 40 mph. - Except for four lower speed zones, speed limit is 60 mph the rest of the way to Picacho
979.7 Picacho - junction with main line, 25 mph turnout, no equation with main line milepost given. Likely to be 937.0.
Summary: Phoenix Line, 209.0 miles long, 70.7 miles out of service, over 100 miles with speed limits of 25 mph or less. Massive rebuild effort required. Would suspect that condition of line today is no better than and probably worse than it was in 2004.