John,
The roundhouse would be behind the left shoulder of the photographer. The 2 tracks right in front of the garage (one with locomotive and the other with the gondola and box car)would be the ones that ran behind the roundhouse and water tank.
I think the track in the middle is the turntable lead, coaling, and ashpit track. I don't have my books here handy at work to confirm that, just going from memory.
The depot is out of the photo on the right side about right accross from where the crossbuck is.
The 2 boxcar sheds in the foreground are the ones that are still there.
Jeff