Eric, most of the eastern railroads accessed Wood St Yard by using the CJ. The Monon most likely would have gotten on the CJ at 40th St on the C&WI, west past the stockyards and Ashland Ave Yard, north through Brighton Park, Ash St and 26th St to the west end of Wood St near 14th St. Here is a photo showing EL and N&W light trains about to head back to their own yards.
The B&O train is leaving Robey St Yard which was adjacent to Wood St to the north. B&OCT's Western Ave Tower can be seen in the right background behind the Santa Fe boxcar. A short CNW train on the left appears to be waiting for the B&O train to clear the Wood St Yard leads. This was a very busy location and virtually every railroad entering Chicago could be seen there.