CSX is a transportation company. Co. provides rail-based freight transportation services including rail service, the transport of intermodal containers and trailers, as well as other transportation services such as rail-to-truck transfers and bulk commodity operations. Co.'s principal operating subsidiary, CSX Transportation, Inc. (CSXT), provides a link to the transportation supply chain through its rail network, which serves main population centers in various states east of the Mississippi River, the District of Columbia and the Canadian provinces of Ontario and Quebec. CXST is also responsible for Co.'s real estate sales, leasing, acquisition and management and development activities.