Union Pacific Corporation is one of America's leading transportation companies. Covering 23 states across two-thirds of the United States, its principal operating company, Union Pacific Railroad, is the largest railroad in North America. Union Pacific's largest single customer is steamship company, APL Limited, followed by General Motors. The railroad is also America’s largest hauler of chemicals. It operates approximately 33,000 route miles and runs competitive long-haul routes between all major West Coast ports and eastern gateways, and serves the six key gateways to Mexico.