The BNSF Railway (reporting mark BNSF) is one of the largest freight railroad networks in North America, second to the Union Pacific Railroad (UP) (its primary competitor for Western U.S. freight), and is one of seven North American Class I railroads. It has 44,000 employees, 32,500 miles (52,300 km) of track in 28 states, and over 8,000 locomotives. It has three transcontinental routes that provide rail links between the western and eastern United States. BNSF trains traveled over 169 million miles in 2010, more than any other North American railroad. The BNSF and UP have a duopoly on all transcontinental freight rail lines in the Western U.S. and share trackage rights over thousands of miles of track. According to corporate press releases, the BNSF Railway is among the top transporters of intermodal freight in North America. It also hauls bulk cargo. For instance, the railroad hauls enough coal to generate roughly ten percent of the electricity produced in the United States. Headquartered in Fort Worth, Texas, the railroad is a wholly owned subsidiary of Berkshire Hathaway Inc.