Southern Pacific's DVRVF (Denver, CO - Roseville, CA) piggyback train glides west along the old Rio Grande at Riverton, Utah. The DVRVF-OADVF trains utilized dedicated sets of EMD GP60s between Denver and Salt Lake City in the early 1990s. The SP 9721 continues to wear its original SP number and speed lettering in 2012, working Union Pacific locals in the midwestern states.