the union pacific
The Union Pacific Railroad, headquartered in Omaha, Nebraska, is the largest railroad network in the United States. James R. Young is president, CEO and Chairman.
UP's route map covers most of the central and western United States west of Chicago and New Orleans.
As of 2005, UP operates on 32,426 miles (52,185 km) of track, of which it owns outright 26,949 miles (43,370 km), both numbers representing the highest amount of any railroad currently operating in the United States