SemGroup also serves as General Partner of Rose Rock Midstream, L.P., a limited partnership recently formed by SemGroup Corporation to own, operate, develop and acquire a diversified portfolio of midstream energy assets SemGroup® Corporation is a publicly held company that moves energy through a network of pipelines Our business - safely moving energy throughout the United States, Canada, Mexico and the United Kingdom Each step we take demonstrates the vast experience of our employees, their dedication to add value to our customers' business, and their desire to bolster our relationships