At its inception, Amtrak's Empire Builder used the ex-NP route between Seattle and Spokane, via Pasco, shifting to the Stevens Pass route on October 25, 1981 when the Portland section started service to Pasco.
Seattle to Auburn
Auburn to Pasco
Pasco to Spokane
From its inception, Amtrak's Empire Builder used the ex-GN route between Fargo and Minneapolis (St. Anthony), via Willmar, until October 1, 1979 when it took up the present route on the termination of the North Coast Limited on that route.
Fargo to Breckenridge
Breckenridge to Benson
Benson to Willmar
Willmar to Lyndale Junction (MInneapolis)
From its inception until February 28, 1978, Amtrak's Empire Builder used the ex-Great Northern station in Minneapolis (on the Willmar route), running between it and Hoffman Avenue on the ex-GN line through St. Anthony and Merriam Park.
Lyndale Junction to Minneapolis Junction
Minneapolis Junction to St. Anthony
St. Anthony to Westminster
Westminster to Hoffman Avenue