SemGroup® Corporation (NYSE:SEMG) and Rose Rock Midstream, L.P. (NYSE:RRMS) will attend the 2012 Morgan Stanley MLP and Diversified Natural Gas Corporate Access Event in New York City on Thursday, March 8, 2012. SemGroup and Rose Rock Midstream Chief Executive Officer Norm Szydlowski and Chief Financial Officer Bob Fitzgerald will conduct one-on-one meetings with members of the investment community. The presentation materials used during the conference will be accessible on the SemGroup website at www.semgroupcorp.com and the Rose Rock Midstream website at www.rrmidstream.com on Thursday, March 8, 2012. About SemGroup Based in Tulsa, Oklahoma, SemGroup® Corporation is a publicly traded midstream service company providing the energy industry the means to move products from the wellhead to the wholesale marketplace. SemGroup provides diversified services for end users and consumers of crude oil, natural gas, natural gas liquids, refined products and asphalt. Services include purchasing, selling, processing, transporting, terminalling and storing energy. SemGroup®, is a registered trademark of SemGroup Corporation.About Rose Rock Midstream Rose Rock Midstream, L.P. (NYSE: RRMS) is a growth-oriented Delaware limited partnership recently formed by SemGroup® Corporation (NYSE: SEMG) to own, operate, develop and acquire a diversified portfolio of midstream energy assets. Rose Rock Midstream provides crude oil gathering, transportation, storage and marketing services. Headquartered in Tulsa, OK, Rose Rock Midstream has operations in six different states with the majority of its assets strategically located in or connected to the Cushing, Oklahoma crude oil marketing hub.