From Pioneer Sq Stn & 3rd Av - James - Bay C tram to Seattle airport, fly to St. Louis airport, then train to St. Louis. 5hrs 57min $144. From Seattle, WA train to Chicago, IL then train to St. Louis, MO. 2days 02hrs $332. From Seattle, WA train to Portland, OR, line 1343 bus to Salt Lake City, UT, bus to Denver, CO, then bus to St. Louis, MO. 2days 04hrs $504. From Seattle drive to St. Louis. 33hrs 18min $269.