RRMS Rose Rock Midstream, L.P. Common Units Representing Limited Partner Interests

In a release issued under the same headline earlier today by SemGroup® Corporation (NYSE:SEMG), the dividend date should be May 29, to all common shareholders of record on May 18. The corrected information follows:

The SemGroup board of directors declared a quarterly cash dividend to common shareholders of $0.38 per share, resulting in an annualized distribution of $1.52 per share. This represents a 12% increase from the previous quarterly dividend of $0.34 and a 58% increase year-over-year. The dividend will be paid on May 29, 2015 to all common shareholders of record on May 18, 2015. The company is targeting a dividend growth rate for 2015 of 50% to 60% year-over-year and an annual growth rate of approximately 30% to 40% over the next three years.

CONTACT: Investor Relations:
         Alisa Perkins
         918-524-8081
         investor.relations@semgroupcorp.com
         
         Media:
         Kiley Roberson
         918-524-8594
         kroberson@semgroupcorp.com