In 1992 Union Pacific 4-6-6-4 Challenger number 3985 made a big trip east from Wyoming to CSX country to participate in the Santa Claus train on the Clinchfield Railroad line. “Challenger Goes East” highlights some of the eastern territory covered by Union Pacific 4-6-6-4 “Challenger” number 3985 as it heads for Clinchfield country. We see two- camera coverage of the Louisville to Cincinnati segment along the former Louisville and Nashville route. From KC Tower in Covington, Kentucky the train continues east along the former Chesapeake and Ohio railroad toward Huntington, and we chase it about as far as Maysville where it continues in the dark. Several days later we see the Challenger made-up as Clinchfield 676 heading down the Big Sandy Subdivision of the C&O to connect to the Clinchfield Railroad, and operate along that line down to Kingsport, Tennessee. (See the Snata Train itself on the GSVP video “Santa’s Challenger”.) We catch Union Pacific 3985 on its homeward journey from Cincinnati, Ohio to Seymour, Indiana on the former Baltimore and Ohio Railroad. Union Pacific and CSX cooperated on this monster trip, and its unlikely to happen again. This is the last articulated locomotive to operate east of the Mississippi River (N&W 1218 last operated in 1991).