From the junction with the Milwaukee West line at its Franklin Park (MP 39.3 on the IHB), west of Tower B 12, where the double track connection turns from east-southeast to south, past grade crossings with Franklin Avenue and Chestnut Street, and the junction with the original Soo Line (later Wisconsin Central, now Canadian National) at its Franklin Park, with its single track connection trailing in on the east side at Grand Avenue (MP 38.8 on Track 1), the IHB Main Line heads south, Two Main Tracks, CTC, maximum speed 25 mph, past a grade crossing with Grand Avenue, a crossover at CP Norpaul (MP 38.3), north end of the three track Norpaul Yard on the west side, within which the line jogs south-southeast, with 25th Avenue bridging overhead, and then south again, past a bridge over North Avenue, ending, with an extra track to the west, at crossovers at CP Rose (MP 37.0), where the maximum speed rises to 30 mph.
There is a wye on the west side, off the extra track to the west (No. 21 Running Track), with the connection west to Proviso Yard, past a bridge over Lake Street and a signal bridge overhead, with a crossover from that extra track having a handthrow switch on Track 2 at Lake Street (MP 36.3) before the south leg of teh wye trails into the extra track, a bridge over the former C&NW West Line, a crossover, the junction with a southwest quadrant connector from the former C&NW West Line (at Provo Junction) onto the extra track to the west, and then a crossover from that track at CP Hill (MP 35.9), a bridge over St. Charles Boulevard, a signal bridge at the end of CTC and start of double-track, current-of-traffic (Rule 251) at Washington Boulevard (MP 35.4), and the St. Charles Street crossover.
A bridge over Washington Boulevard precedes a north-facing Intermediate Signal at MP 35.4, a handthrow switch on Track 1, with a north-facing industrial spur to the east (that formerly went to Madion Park) at Bellwood (MP 35.1), a bridge over Madison Street, a south-facing Intermediate Signal at MP 34.7, an extra track to the east (the West PAss), a bridge over I-290, a former bridge over the erstwhile Chicago Great Western and Chicago, Aurora & Elgin, signals and crossovers, a bridge carrying Roosevelt Road overhead, and the junction (northeast quadrant connector with the former Illinois Central Iowa line at Broadview (MP 33.9), and a bridge carrying the IC Iowa line overhead.
There is a bridge carrying 22nd Street overhead, the West Pass ends on the east side, Intermediate Signals on a signal bridge at MP 32..1/2, a grade crossing with 21st Street, an extra track on the east side, a grade crossing with Harding Avenue, a crossover to that extra track to the east, where LaGrange Yard trails in, a grade crossing with Shawmut Avenue, the junction (northeast (West Wye), off the extra track, which then ends, and southeast quadrant (East Wye) connectors) with the former CB&Q (which bridges overhead) at CP LaGrange (MP 31.0), where Two Main Tracks, CTC, resume and the maximum speed drops to 25 mph, with Ogden Avenue bridging overhead within the East Wye.