From the junction with the transcontinental passenger line at Isleta (MP 915.0), the original main line south from Albuquerque to El Paso, single track, Track Warrant Control, with speed limit 20 mph at the junction and 49 mph (due to the lack of signaling) thereafter, continues south-southwest, past the 3,546 ft. siding at Isleta, and turns south, past the 4,136 ft. siding at Los Lunas (MP 922.4), and Chloe (MP 927.4), to Belen Junction (MP 932.4)), where the speed limit is 10 mph.
The Belen yard and on-line fuel racks, a thousand-mile inspection point, are on the east side of this southerly-heading line between Belen Junction and El Paso Junction, south of the SR 309 overbridge, while the erstwhile passenger depot is on the west side, on 1st Street, on this 30 mph, Eight Main Tracks (including the on-line fuel-racks), CTC, line, which has crossovers at Belen (MP 933.1), at an altitude of 4,785 feet.