Nature of Operations

6 Months Ended

Jun. 30, 2011

Nature of Operations

Nature of Operations

1. NATURE OF OPERATIONS

Carrizo Oil & Gas, Inc. is an independent energy company which, together with its subsidiaries (collectively referred to herein as the "Company"), is engaged in the exploration, development and production of oil and gas in the United States and the U.K. North Sea. The Company's current operations are principally focused in proven, producing oil and gas plays in the Barnett Shale in North Texas, the Marcellus Shale in Pennsylvania, New York and West Virginia, the Eagle Ford Shale in South Texas, the Niobrara Formation in Colorado and the Huntington Field located in the U.K. North Sea.