A Class 1 railroad is defined as any railroad with annual revenue of more than $504,803,294 (the 1992 threshold of $250 million, set by the ICC, adjusted for inflation). There are six Class 1 Railroads operating in the United States; BNSF, CSX, CN, CPKC, NS and UP. Burlington Northern was formed through the mergers of Great Northern and Northern Pacific in 1970, and then merged with ATSF in 1995 to form BNSF. BNSF is one of the largest freight railroads in the country with over 32,000 miles of rail.