Atmos Energy

Barnett Gathering Company, LLC

Barnett Gathering, LP

Centana Intrastate

Chesapeake Energy Corporation

Crosstex Energy

DCP Midstream

Devon Energy Operating Co. LP

Devon Gas  Services

Enbridge Gathering LP

EOG Resources

HMG Engineering

Nor Tex Gas Storage, LLC

Norwood Land, LLC

Pioneer Natural Resources USA, Inc.

Targa Resources, Inc.

The Cumming Company

Texas Midstream Gas Services, LLC

Williams