These two passenger coaches are the last 86 seat Northern Pacific 600 series coach and the last 88 seat 600 series Northern Pacific coach. They have been in continuous passenger service since they were built as Pullman parlor cars assigned to the Pennsylvania Railroad in 1910 and 1912. They were both regularly used during the popular Casey Jones Excursions in the last years of the Northern Pacific Railway that explored branch lines leading to towns and cities throughout western Washington.