TC PipeLines, LP (the Partnership) acquires, owns and participates in the management of energy infrastructure businesses in North America. The Company�s pipeline systems transport natural gas in the United States. The Partnership is managed by the Company�s General Partner, which is an indirect, wholly-owned subsidiary of TransCanada. The Company has equity ownership interests in four natural gas interstate pipeline systems. The Company�s pipeline systems include Great Lakes, Northern Border, GTN, Bison, North Baja and Tuscarora. Great Lakes connect with the TransCanada Mainline at the Canadian border near Emerson, Manitoba, Canada and St. Clair, Michigan, near Detroit. Great Lakes are a bi-directional pipeline that can receive and deliver natural gas at multiple points along its system. Tuscarora extends between GTN near Malin, Oregon to its terminus near Reno, Nevada and delivers natural gas in northeastern California and northwestern Nevada.