Union Pacific 1243 is unquestionably the oldest "Ten Wheeler" owned by the Union Pacific Railroad. The 1243 was built in 1890, and it operated on various branch lines of the Union Pacific in the state of Nebraska. From the 1930s until 1956 the 1243 operated on the railroads Encampment Branch in the state of Wyoming. That same year, the 1243 was retired from active service. First, it resided in Rawlins, Wyoming before going to Cheyenne, Wyoming. In 1990 the 1243 was cosmetically restored, and that same year, the 1243 rode a flat car and rode a special train. After that, the locomotive was sent to Omaha, Nebraska, where it was placed on display at the Western Heritage Museum in October 1996. This engine is called the "Harriman Engine", because it is the only engine owned by the Union Pacific Railroad from the era when E.H. Harriman controlled the Union Pacific.