Semgroup Corp provides gathering, transportation, storage, distribution, marketing, and other midstream services to producers, refiners of petroleum products, and other market participants located in the United States and Canada. The company utilizes pipelines, gathering systems, terminals, processing plants, and other distribution assets to service its host of customers. Lines of business for Semgroup are divided between the U.S. Liquids, U.S. Gas and Canada segments. The U.S. Liquids segment operates crude oil pipelines, truck transportation, storage, terminals, and marking businesses in the U.S. and is the largest segment. The other segments provide natural gas gathering, processing, and marketing services in the U.S. and Canada.