The former Chicago & Northwestern Station (MP 0.0) is now the Ogilvy Transportation Center, occupying the lower floors of an office high-rise at Madison Street and Canal Street on the west side of the South Branch of the Chicago River. The stub-end platforms, behind the office tower, are elevated above street level, and have a concourse at the south end of the platforms. Each platforms has two tracks associated with it, one on either side, with the whole covered by a connecting set of umbrella sheds—a Bush train shed. There are eight stub-end platforms serving 16 terminal tracks, with the whole bridging over a street within the platform area, north of which is a second set of ticket windows and platform entrances in an east-west arcade at street level, below the platforms and mid-way along their length. The station throat, full of double-slip switches and scissors crossovers, is north of the north-south platforms, with a small locomotive servicing area on the east side as the number of tracks narrows to four at Lake Street (MP 0.2), where the CTA Elevated Green Line passes overhead on a steel viaduct, there is a signal tower in the east side and operating offices on the west side, and the tracks bridge over the eponymous street below on a through girder bridge.
The former Milwaukee Road tracks from the north side of Chicago Union Station pass below the concrete viaduct on which the former C&NW tracks are supported at this point. At Clinton Street (MP 0.4), named for the north-south street on the west side of the station, there is a signal bridge overhead, and the four tracks of the Geneva subdivision turn to the west, under a signal bridge and bridging over the eponymous street, while the two tracks of the Kenosha subdivision continue ahead to the north, under their own signal bridge.
The speed limit within the station is 10 mph, rising to 15 mph for passenger and TOFC trains, and 10 mph for freight trains, at MP 0.3.