In
railroad lingo, a bull is a railroad
cop, whose job it is to watch out for safety and prevent trespassing and theft on railroad property. Bulls may be assigned to particular
yards, or they may
patrol at random over a wide-ranging territory. They often co-operate with local authorities when the occasion calls for it.
Much of the bull's time is actually spent monitoring employee safety, which is a high priority for railroad companies such as BNSF and Union Pacific.
Railroad police may be easily spotted by their white, American trucks, usually Jeep Cherokees but occasionally Chevrolet Suburbans. Train-hoppers and other deviants would do well to hide in the nearest bushes upon spotting one of these vehicles.