During late 2005 and early 2006, three of UP's "heritage" locomotives -- Missouri Pacific 1982, MKT 1988, and
UP 4141 (in a special paint scheme to commemorate the George Bush Presidential Library
in College Station) -- operated for several months between Fort Worth and Houston.
On a February morning in 2006, I caught southbound
M FWEWB departing Fort Worth for Houston with the Missouri Pacific "heritage" locomotive leading the train.