[3][4] The line was also operated by passenger trains by the Great Northern Railway and Union Pacific Railroad under a joint service agreement.

In 1994 and 1995, the station was inundated with water damage when the nearby Cowlitz River peaked over the dike at 22 feet (6.7 m) and flooded the basement and platform area, which ultimately led to the approval of the remodel.

[8] Although the Amtrak Cascades runs between Eugene, Oregon and Vancouver, British Columbia, Canada, there is no train that starts at one terminus and ends at the other.

However, each day eight Amtrak Cascades trains (four northbound and four southbound) stop at the Kelso Multimodal Transportation Center.

[9] The Coast Starlight has runs one train daily in each direction between Los Angeles, California and Seattle.

A head-on crash between a Burlington Northern and Union Pacific train occurred just south of Kelso on November 11, 1993.