Anadarko Petroleum Corporation
http://www.anadarko.com/
Apache Corporation
http://www.apachecorp.com/
Bill Barrett Corporation
http://www.billbarrettcorp.com
BHP Billiton Petroleum
http://www.bhpbilliton.com
Cabot Oil & Gas Corporation
http://www.cabotog.com
Chesapeake Energy Corporation
http://www.chesapeake-energy.com
Devon Energy Corporation
http://www.devonenergy.com/
El Paso Exploration & Production
http://www.elpaso.com/
Energen Resources Corporation
http://www.energen.com
EOG Resources, Inc.
http://www.eogresources.com
Forest Oil Corporation
http://www.forestoil.com
HighMount Exploration & Production LLC
http://www.loews.com/loews.nsf/highmount.htm
Linn Energy LLC
http://www.linnenergy.com
Mariner Energy, Inc.
http://www.Mariner-Energy.com
Newfield Exploration Company
http://www.newfld.com/
Noble Energy, Inc.
http://www.nobleenergyinc.com
Occidental Oil & Gas Corporation
http://www.oxy.com
Pioneer Natural Resources Company
http://www.pioneernrc.com/
Plains Exploration and Production Company
http://www.plainsxp.com/index.php
Questar Exploration & Production Company
http://www.questar.com/qmr/qep/index.html
Seneca Resources Corporation
http://www.natfuel.com/seneca
Southwestern Energy Company
http://www.swn.com
St. Mary Land & Exploration Company
http://www.stmaryland.com
Ultra Petroleum Corp.
http://www.ultrapetroleum.com
Whiting Petroleum
Corporation
http://www.Whiting.com
The Williams Companies
http://www.williams.com/
XTO Energy, Inc.
http://www.xtoenergy.com/
