In addition to covering the Great Northern-Northern Pacific-Union Pacific pool trains between Portland and Seattle, this timetable unfolds to the equivalent of six pages to also show the Great Northern Internationals between Seattle and Vancouver. While the Internationals were run solely by the Great Northern, each of the three pool trains was run by one of the three railroads.
The timetable doesn’t say which railroad ran which train, but trains 407 & 408, which the timetable noted had a Holiday Lounge car, were Northern Pacific; trains 457 & 458, listed as a Domeliner, were Union Pacific; leaving trains 401 & 460 as the Great Northern. Train 401 was coach-only while 460 also carried a sleeping car from Seattle to Portland that would be put on Union Pacific’s City of Portland to Chicago, allowing that train to compete for Seattle-Chicago passengers with GN’s own Empire Builder.
In 1960, train 401 from Portland to Seattle was an overnight train, leaving Portland at 11:45 pm and arriving in Seattle at 6:00 am, in time to catch the morning International to Vancouver. A 1958 timetable shows four trains in pool service, one of which went overnight in both directions. When they reduced service to three trains per day, GN must have decided to keep its northbound overnight train to connect with its Vancouver train. I suspect this didn’t last long.