Dallas, Texas (October 23, 2012) – Summit Midstream Partners, LLC (“Summit Investments”) announced today that it has closed the $207 million acquisition of ETC Canyon Pipeline, LLC (“Canyon”) from La Grange Acquisition, L.P., a wholly-owned subsidiary of Energy Transfer Partners, L.P. Canyon gathers and processes natural gas in the Piceance and Uinta Basins in Colorado and Utah, primarily under long-term, fee-based agreements with more than 50 customers including WPX Energy, Noble, Black Hills, Laramie, Encana, ExxonMobil, and Antero. The gas gathering and processing system consists of more than 1,600 miles of pipe, 44,000 horsepower of compression, processing assets with a total capacity of 97 MMcf/d, and two NGL injection stations.

The Canyon assets will be held in Red Rock Gathering Company, LLC (“Red Rock”), a wholly-owned subsidiary of Summit Investments, which also owns a gathering system in the Sandwash Basin in northern Colorado that was acquired in the second quarter of 2012.

Steve Newby, President and Chief Executive Officer of Summit Investments said, “We are excited about the addition of Canyon to Red Rock Gathering Company, LLC. Red Rock solidifies our position in the Rockies as a premier midstream operator and should allow the company to capture new business opportunities in the region. We are particularly excited that this acquisition provides the company with increased exposure to the liquid-rich parts of the Mancos and Niobrara Shale formations in the Piceance Basin, where Canyon and Summit Midstream Partners, LP, through its ownership of the Grand River natural gas gathering system, operate. Red Rock also provides Summit Investments with additional opportunities to capitalize on growth projects supporting traditional Mesaverde formation production and new production in the Uinta and Sandwash Basins.”

Summit Investments also announced today that Red Rock has two new fee-based commercial agreements with WPX Energy Rocky Mountain, LLC and Black Hills Exploration and Production, Inc. Each of these new agreements include long-term acreage dedications and collectively provide more than 350 Bcf of minimum volume commitments. Red Rock will expand its existing gathering and compression services for WPX by constructing gas gathering infrastructure to connect new WPX production in the Rifle, CO area. Red Rock will also construct a processing plant and related gas gathering infrastructure in the DeBeque, CO area, which will support Black Hills’ future development of their liquids-rich Mancos and Niobrara acreage. The WPX project will be developed and commissioned over the next several years and the Black Hills project is expected to be completed by the end of 2013.

Newby further commented, “These new organic growth projects at Red Rock enable us to leverage our asset development skill set and drive contracted, fee-based cash flow growth over the next several years.”

About Summit Midstream Partners, LLC
Summit Midstream Partners, LLC is a growth-oriented midstream energy company focused on owning and operating midstream energy infrastructure that is strategically located in the core areas of unconventional resource basins, primarily shale formations, in North America. Through its ownership of (i) Summit Midstream GP, LLC, the general partner of Summit Midstream Partners, LP; (ii) a 69.1% limited partner interest in Summit Midstream Partners, LP (NYSE: SMLP); and (iii) its 100% ownership of Red Rock Gathering Company, LLC, Summit Investments provides fee-based natural gas gathering, processing and compression services, supporting some of the largest production companies in North America, in four unconventional resource basins: (i) the Piceance Basin, which includes the Mesaverde, Mancos and Niobrara Shale formations in western Colorado; (ii) the Fort Worth Basin, which includes the Barnett Shale formation in north-central Texas; (iii) the Sandwash Basin in northern Colorado; and (iv) the Uinta Basin in Utah. Summit Investments is headquartered in Dallas, TX with offices in Houston, TX, Denver, CO and Atlanta, GA.

Summit Investments was formed in 2009 by members of management and funds controlled by Energy Capital Partners II, LP. Together with its affiliates, Energy Capital Partners is a private equity firm with over $7 billion in capital commitments that is focused on investing in North America's energy infrastructure. In August 2011, Energy Capital Partners sold an interest in Summit to GE Energy Financial Services. GE Energy Financial Services invests globally in essential, long-lived and capital- intensive energy assets.

For more information, visit Summit’s website at www.summitmidstream.com, Energy Capital Partners at www.ecpartners.com and GE Energy Financial Services at www.geenergyfinancialservices.com.

INVESTOR CONTACT:
Summit Midstream Partners, LLC Marc Stratton
Vice President and Treasurer 214-242-1966
ir@summitmidstream.com