The Buttonwillow Deep Prospect was acquired in November 2011 as part of a transaction with a private company. Targets include the Monterey/McClure shales, 44X and Randolph sand oil targets. Analog fields include North Shafter (10 mmboe) and Rose (4.8 mmboe). Underground has rights to any data generated on its holdings through a joint Occidental/Venoco 3D seismic survey currently underway.