HOUSTON, Texas – On February 18th 2011, Frontier Gas Services (“FGS”) entered into a definitive agreement to sell its assets in the Fayetteville Shale and the Granite Wash plays to Crestwood Midstream Partners, L.P. (“Crestwood”) for $353 million in total consideration (including a $15 million contingent payment). Crestwood LP expects to finance the purchase through a combination of equity and debt. The transaction is expected to close in late March 2011.

The Frontier Fayetteville assets consist of approximately 110 mi les of high pressure and low pressure gathering pipelines with capacity of approximately 510 million cubic feet per day (“MMcf/d”), treating capacity of approximately 165 MMcf/d and approximately 35,000 hp of compression. The Fayetteville systems interconnect with multiple interstate pipelines which serve the Fayetteville Shale and are supported by long-term, fixed-fee contracts with blue chip producers who have dedicated approximately 100,000 acres in the core of the Fayetteville Shale to Frontier.

The Frontier Granite Wash assets currently consist of a 28 mile pipeline system and a 36 MMcf/d cryogenic processing plant in the Texas Panhandle. The Granite Wash area has emerged as a highly economic liquids-rich natural gas play with active drilling programs by area producers. The Granite Wash assets are supported by long-term contracts with producers which have substantial Texas Panhandle area drilling programs underway. Crestwood LP plans to install a second processing plant with 60 MMcf/d of capacity that is expected to be in service by the end of201 1 to provide additional capacity to support growth in volumes from this region.