West Green River Dispatcher Dick Christensen is updating the train graph at the 4th Subdivision desk in Cheyenne. Christensen was the long time second trick (3-11pm) dispatcher for the railroad between Green River, WY and Ogden, UT. He was savvy and excelled at looking into the future and "setting up" his railroad so that traffic ran smoothly.
The railroad is CTC from Green River (right) to Granger, where the Oregon Short Line diverges; then it's 53 miles of ABS territory to Aspen where a short stretch of CTC governs movements through Aspen and Altamont tunnels (above the graph). Then it's another 73 miles of ABS territory down the mountain to Strawberry. The US&S "pup" CTC machine on the left handles the railroad from Strawberry into Ogden.
One of the speakers was used to monitor radio conversations, the other was the Wahsatch annunciator - an open mike by the eastward track so that one would know when eastbounds were cresting the long grade from Ogden.
Within less than a decade the entire railroad was handled from one big room in Omaha but there's not a computer in the house at this time.