Carrizo Oil & Gas, Inc. (NASDAQ: CRZO), an independent energy company, engages in the exploration, development, and production of oil and gas in the United States and the United Kingdom. The company holds interest in crude oil and liquids plays in the Eagle Ford Shale in south Texas; the Niobrara Formation in Colorado; the Utica Shale in Ohio and Pennsylvania; and the Huntington Field in the U.K. North Sea. It also owns interest in natural gas plays in the Barnett Shale in North Texas; and the Marcellus Shale in Pennsylvania, New York, and West Virginia; as well as in the onshore Gulf Coast area and the Camp Hill field in Texas. As of December 31, 2011, the company had a proved oil and gas reserves of 935.6 billion cubic feet equivalent comprising 728 billion cubic feet of natural gas; 30.5 million barrels of oil or other liquid hydrocarbons (MMbbls) of oil and condensate; and 4.1 MMbbls of natural gas liquids, as well as operated 349 gross producing oil and gas wells. Carrizo Oil & Gas, Inc. was founded in 1993 and is based in Houston, Texas.