At Tucson, 36th Street (MP 987.7), where the speed limit is 45-40, the SP "North Line" once continued southeast, but today's Two Main Track, CTC, main line turns south to cut over to the erstwhile EP&SW right-of-way once known as the "South Line", turning southeast at South Line Junction to take up that EP&SW right-of-way, with speed limit 79-70, passing a detector at MP 991.5, Wilmot (MP 994.8), where a spur from Davis-Monthan Air Base trails in from the north, Rita, and detectors at MP 997.9. The split between the two eastward tracks, the original SP (now "Track 2") down in the curving valley of the local watercourse, and the former EP&SW (now "Track 1") up on the level ground, is at Vail Crossovers (MP 1000.0), where the ex-SP "North Line" once trailed in from the north. At this point, Track 1 is the more southerly of the two lines, both of which are still heading southeast. Track 2 passes Vail (MP 1003.5) as it descends into a cut with a speed limit of 35 mph, while track 1, on the plain above, passes through Empire.
At Cienega Creek, in a nature reserve, the upper track (Track 1) turns northeast, also with speed limit 35 mph, and crosses the lower track (Track 2) on a steel trestle that strides northeast across the desert before the line turns southeast again to pass Marsh, a detector at MP 1016.4, and Catalina before turning east to the 4,063 ft. summit at Mescal (MP 1023.3). Track 2, where the speed limit falls to 28-25, twists back and forth past Irene, Pantaro, Buell, where it turns south and then makes a counter-clockwise horseshoe back to the north, with a detector at MP 1017.5, with part of the line on an embankment and just one bridge over a dirt road on this whole stretch, and then turns east past Amole to Mescal (MP 1023.3), where there are crossovers as the tracks come back together. At Mescal, all the onetime railroad artifacts (semaphores, water tank, coaling station, etc.) are now gone, with only the minimal number of modern signals present. The former EP&SW "South Line" once turned away southeast, and then south, at this location.
East of Mescal, where there is a dirt road grade crossing, and through Benson to Cochise, were once there was only a single track, there is now double track (operated as Two Main Tracks, CTC, not as direction of traffic single lines in each direction). The original SP "North Line" continues east, with speed limits 60-55, past Intermediate Signals and detectors at MP 1025.9, crossovers at Chamiso (MP 1029.3), a cutting, detectors at MP 1030.7, as the line turns southeast, beneath dual road bridges overhead, and then curves around east again, descending past a grade crossing, a bridge over drainage, and a grade crossing just west of the shack, to Benson (MP 1032.6), where there is a passenger station (shack) on the south side of the line, an old depot on the south side, a grade crossing, and a road alongside to the south, followed by a wye junction in the open country as the main line curves northeast, with the southward San Pedro & Southwestern Railroad, which now operates the former EP&SW line south of Benson Junction, some miles to the south, a bridge over the San Pedro River, crossovers at Fenner (MP 1035.0), where the line turns northeast and starts to climb steeply, a dirt road grade crossing, and detectors at MP 1036.7, where the line turns southeast as cuttings and embankments alternate, and at MP 1038.1, where the line turns south and the speed limit drops to 45-40.
There are intermediate signals at MP 1040.x, two bridges over gullies, the line turns east past crossovers at Sibyl (MP 1043.6), where the speed limit is 40 mph, there is a bridge over a gulley, and the line turns northeast, north, east and east-northeast, with Intermediate Signals in among the curves, past a dirt road grade crossing, crossovers at Tully (MP 1050.3) and detectors at MP 1051.8 to Dragoon (MP 1053.5), site of a 4,613 ft. summit, where a branch to Johnson once headed north and the speed limit rises to 55-50. The terrain east of Tucson, and especially between Benson and Dragoon, has become quite mountainous in nature, as it climbs up toward the various summits. The line turns east, and then north-northeast at Mancero (Intermediate Signals), past detectors at MP 1059.3, crossovers at Apache (MP 1061.3), AZEX Spur, where a line to the AZEX Cochise Power Plant heads east, a dirt road grade crossing, extra track (a double-ended spur) on the east side, and Cochise (MP 1065.8), where the two Main Tracks reduce to single track, CTC, and an SP branch to Douglas once headed south-southeast.
The terrain turns into areas of large salt flats and dry lakes, as the line continues northeast, across Wilcox Dry Lake, past a detector at MP 1071.8, Hado, the 8,379 ft. siding on the southeast side, with extra track on the southeast side at Willcox (MP 1072.6-1074.3), where a spur to the Mascot Mine at Dos Pasos once headed east, a dirt road grade crossing, a detector at MP 1077.0, Drury, where the line turns northeast, Raso (MP 1081.2), a 4,380 ft. summit, where Two Main Tracks begin again (for the westbound ascent that ends at this point) and the line gradually curves east as it descends, with speed limit 65-60, past Intermediate Signals at MP 1085.x, a bridge over a gulley, Intermediate Signals at MP 1088.x, detectors at MP 1088.2, a bridge over a gulley, Intermediate Signals at MP 1090.x and Alrich, a bridge over a gulley, a bridge over a road, and the dual I-10 road bridges overhead, to Luzena (MP 1091.8), the foot of the grade, where single track begins again (still CTC) and the speed limit rises to 79-70. The line turns just south of due east, past a detector at MP 1094.0, Cholla, the 7,209 ft. siding on the south side at Bowie (MP 1096.7-1098.3), where the Arizona Eastern Railway serving the copper mines at Globe, heads away north at a wye, there is a grade crossing within the siding, and the depot used to be on the south side, where a road runs alongside through the town, a hold signal at CP S1100 (MP 1099.6), two bridges over gullies, a detector at MP 1102.6, two bridges over gullies, I-10 runs just beyond a frontage road to the south, there are five bridges over gullies, a dirt road grade crossing, a bridge over a gulley, three dirt road grade crossings, three bridges over gullies, the 8,236 ft. siding on the north side at Olga (MP 1105.4-1107.0), three bridges over gullies within the siding, and a detector at MP 1110.0.
Two Main Tracks, CTC, begin again at San Simon (MP 1112.5), there is a grade crossing, Intermediate Signals at MP 1114, a grade crossing, a bridge over drainage, detectors at MP 1119.0, crossovers at Vanar (MP 1120.8), I-10 alongside to the east/south, and crossovers at Cavot (MP 1126.2), where the speed limit falls to 45-40 and the line crosses from Arizona into New Mexico, curving around and then turning southeast, south, and northeast again, and a dirt road grade crossing, a short double-ended spur on the south side just west of the crossovers at Steins (MP 1129.7), where the speed limit is 55-50, with detectors at MP 1131.9, as the line turns northeast, and I-10 alongside to the southeast. Single track, CTC, resumes at Mondel (MP 1134.6), where the speed limit becomes 79-70,, and the line passes a detector at MP 1136.9, three bridges over drainage, the 8,360 ft. siding at Gary (MP 1140.6-1142.3), the former location of a detector at MP 1140.8 and a bridge over drainage before turning east into Lordsburg, where a former SP line to Hachita, on the EP&SW running some way to the south, once headed southeast, the ex-SP "Clifton Branch" (serving the Morenci copper mines) trails in from the west-northwest, the speed limit is 60 mph, there is a bridge over a street below, a street alongside to the south with buildings on the south side only, a passenger station on the south side of the line, where the depot has been replaced by an Amshack, and a 10,850 ft. siding on the south side (MP 1147.6-1149.7).
The line continues east-southeast, and the speed limit rises to 79-70, with I-10 alongside to the south, past a dirt road grade crossing, a detector at MP 1152.0, the 8,378 ft. siding on the north side at Ulmorris (MP 1152.3-1153.9), where the line turns southeast, a detector at MP 1156.3, a bridge over a gulley, Intermediate Signals at MP 1157.2, a bridge over a gulley, the 8,457 ft. siding on the south side at Lisbon (MP 1158.6-1160.0), a dirt road grade crossing, seven bridges over gullies, Intermediate Signals at MP 1163.4, a detector at MP 1165.0, two bridges over gullies, Intermediate Signals, and two bridges over gullies, the 8,362 ft. siding at Separ (MP 1166.3-1168.0), a bridge over a gulley within the siding, a grade crossing at the east end of the siding.
The line turns just north of east at Hidalgo (MP 1171.4), where a long Phelps-Dodge branch from the Hidalgo Smelter trails in, passing Ladim, a detector at MP 1174.3, the 8,385 ft. siding at Wilna (MP 1176.3-1177.9), and a dirt road grade crossing, before crossing the Continental Divide, which is virtually unnoticeable at this point. There is a detector at MP 1181.2, a dirt road grade crossing, the 8,371 ft. siding at Gage (MP 1187.0-1188.6), a grade crossing, a bridge over a gulley, MP 1189, a detector at MP 1192.2, a grade crossing at SR 418, Mongola, a dirt road grade crossing, the 8,351 ft, siding at Tunis (MP 1197.3-1199.0), a bridge over an arroyo, a detector at MP 1202.7, a bridge over an arroyo, a dirt road grade crossing, Intermediate Signals, a dirt road grade crossing, and a hold signal at CP S1207 (MP 1207.2)
On the west side of Deming, the Southwestern Railroad line from Whitewater, and branches beyond that, trails in from the northwest, and an erstwhile EP&SW line from Hermanns, on the EP&SW main line just north of the Mexican Border, once trailed in from the south-southwest. There is a bridge over a divided highway, MP 1208, a grade crossing at Berg street (MP 1208.2) an 8,309 ft, siding at Deming (MP 1208.2-1209.8), and a passenger station on the north side of the line, between the ex-SP and four ex-Santa Fe tracks there, with connecting tracks east of that location. The ex-Santa Fe line heads away east-northeast at the east end of Deming.