Rose Rock Midstream, L.P., is a company that owns, operates, develops and acquires diversified portfolio of midstream energy assets. The Company is engaged in the business of crude oil gathering, transportation, storage, distribution and marketing. The Company is involved in providing midstream energy related services. The Company serves areas that are experiencing strong production growth and drilling activity. For the year ended December 31, 2013, approximately 80% of adjusted gross margin was generated from fee-based contracts, some of which provide for fixed fees that are not dependent on usage, and fixed-margin transactions. The general partner of Rose Rock is Rose Rock Midstream GP, LLC (Rose Rock GP), which is a wholly-owned subsidiary of SemGroup, provides diversified midstream services to the energy industry.