Headquartered in Houston, Texas, Newfield Exploration is an independent company that specializes in the exploration and production of crude oil and natural gas. Its operations in the United States include the Mid-Continent region of Oklahoma and northern Texas, along the Rocky Mountains, southern and coastal Texas, the Gulf of Mexico, and recently in Pennsylvania along the Appalachia Mountains. Newfield also operates internationally through numerous sites offshore of Malaysia and China. By the end of 2009, total proved reserves were 3.6 trillion cubic feet (1.0×10 m) equivalent with approximately 85% of those reserves being located onshore of the U.S. Newfield's present base is estimated to be about 70% natural gas. Today, Newfield has an enterprise value of more than $8.5 billion.