Semgroup Corporation provide gathering, transportation, storage, distribution, marketing, and other midstream services primarily to independent producers, refiners of petroleum products, and other market participants located in the Midwest and Rocky Mountain regions of the United States of America, Canada and the West Coast of the United Kingdom. The Company also maintains and operates storage, terminal and marine facilities at Milford Haven in the United Kingdom that enable customers to supply petroleum products to markets in the Atlantic Basin. It also operates a network of liquid asphalt cement terminals throughout Mexico. The Company conducts its operations through six primary business segments: Crude, SemStream, SemLogistics, SemCAMS, SemMexico and SemGas. On November 1, 2011, the Company contributed the operating assets of its SemStream segment to NGL Energy Partners LP.