At Tucson, 36th Street (MP 987.7), where the speed limit is 40 mph, 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 59-49 on Track 1 and 70-65 on Track 2, passing detectors at MP 991.5, crossovers on a stretch of Double Track, current-of-traffic (Rule 251), Automatic Block Signals at Wilmot (MP 994.8), where there is a 6,485 ft. siding off Track 1 and a 6,699 ft. siding off Track 2, and a spur from Davis-Monthan Air Base trails in from the north, Rita, and a detector at MP 998.8 on Track 1. 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 the CTC 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, Direct Traffic Control (the Vail Block from MP 1000.1 to MP 1010.1) as far as Mescal, with speed limit 70-65, passes Vail (MP 1003.5) as it descends into a cut, while the CTC Track 1, on the plain above, with speed limit 79-70, passes through Empire.
At Cienega Creek, in a nature reserve, the upper track (Track 1) turns northeast, 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 (MP 1012.9), where the speed limit is 65 mph, a detector at MP 1016.4, and Catalina before turning east to the 4,063 ft. summit at Mescal (MP 1023.3), where the speed limit is 40 mph. Track 2, where the speed limit falls to 28-25, twists back and forth past Irene, the end of the Vail Block and start of the Pantano Block at MP 1010.1, a detector at MP 1011.1, Pantano (MP 1012.9), where the speed limit is 40-30, 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, with speed limit 40 mph, past Amole to Mescal (MP 1023.3), where the Pantano Block ends and 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, the line is single track, CTC. The original SP "North Line" continues east, with speed limit 55 mph, past Intermediate Signals and detector at MP 1025.9, an 8,099 ft. siding at Chamiso (MP 1028.2), a cutting, and a detector 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, to Benson (MP 1032.6), where there is a passenger station with depot on the south side of the line, 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, an 8,429 ft. siding at Fenner (MP 1035.0), where the speed limit is 60 mph as the line turns northeast and starts to climb steeply, a dirt road grade crossing, and a detector 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 40 mph.
There are intermediate signals, two bridges over gullies, the line turns east past a 9,197 ft. siding at Sibyl (MP 1043.6), 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, an 8,239 ft. siding at at Tully (MP 1050.3) and a detector at MP 1050.3 to a 15,306 ft. siding at Dragoon (MP 1053.9), site of a 4,613 ft. summit, where a branch to Johnson once headed north and the speed limit rises to 60 mph. 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 a detector at MP 1059.3, Apache (MP 1061.3), AZEX Spur, where a line to the AZEX Cochise Power Plant heads east, a dirt road grade crossing, an 8,416 ft. siding at Cochise (MP 1063.9), where 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 1069.3, 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 the speed limit is 60 mph, 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, and the line gradually curves east as it descends, with speed limit 70-65, past Intermediate Signals, a bridge over a gulley, Intermediate Signals, a detector at MP 1088.1, a bridge over a gulley, Intermediate Signals and Alrich, a bridge over a gulley, a bridge over a road, and the dual I-10 road bridges overhead, to the 9,947 ft. siding at Luzena (MP 1091.8), the foot of the grade, where the speed limit rises to 79-65.
The line turns just south of due east, past a detector at MP 1094.0, Cholla, the 8,209 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, 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.
There is an 8,017 ft. siding at San Simon (MP 1114.2), a grade crossing within the siding, a grade crossing, a bridge over drainage, a detector at MP 1118.0, an 8,026 ft. siding at Vanar (MP 1121.8), where the speed limit is 50 mph, I-10 alongside to the east/south, and a detector at Cavot (MP 1126.2), where 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 10,777 ft. siding at Steins (MP 1129.7), where the speed limit is 70-65, with a detector at MP 1130.5, as the line turns northeast, and I-10 alongside to the southeast, an 8,324 ft. siding at Mondel (MP 1134.6), 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, there is a bridge over a street below, a street alongside to the south with buildings on the south side only, and a passenger station (depot) on the south side of the line (MP 1148.3)
The line continues east-southeast, 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 1156.2, 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, a detector at MP 1163.1, Intermediate Signals at MP 1163.4, 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 1202.3, a bridge over an arroyo, a dirt road grade crossing, Intermediate Signals, and a dirt road grade crossing.
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.