Sempra North American energy infrastructure company based in San Diego

• Member

Laclede Gas Company The largest natural gas distribution company in Missour

• Member

Delta Natural Gas Co.

• Member

Arkansas Oklahoma Gas

• Member

Clearwater Gas System

• Member

Black Hills Energy utility serving Colorado, Iowa, Kansas and Nebraska

• Member

Atlanta Gas Light

• Member

Alagasco

• Member

Williams Companies, Inc. Natural gas pipeline company based in Tulsa, Oklahoma

• Member

Range Resources Corporation Oil & gas driller

• Member

Members