It's interesting to trace the route structure of the long distance trains through some selected Amtrak timetables: At the start of Amtrak in 1971, only the Empire Builder operated; the North Coast Hiawatha was inaugurated within the first year. 01-16-72: Empire Builder (7/8) and North Coast Hiawatha (9/10) both use former NP line from Seattle to Pasco via Auburn to reach Spokane. 06-11-72: Same situation as 01-16-72 05-19-74: Empire Builder (7/8) uses ex-NP line as before. North Coast Hiawatha(9/10) uses ex-GN line via Wenatchee. 06-15-76: Same as 05-19-74 08-30-80: Empire Builder (7/8) uses ex-NP line as before. North Coast Hiawatha terminated a year or two earlier during Carter-era cuts. 08-31-82: Empire Builder uses ex-GN line to Seattle and ex-SP&S line to Portland. Note: While the Empire Builder used the ex-NP line between Seattle and Pasco via Auburn, it used the ex-SP&S line between Pasco and Spokane in one direction and the ex-NP line between Pasco and Spokane in the other direction. This is not discernible from Amtrak timetables!