According to the U.S. Energy Information Administration, U.S. crude oil production averaged 7 million barrels per day (bbl/d) in December 2012 – the highest output since 1992. From EIA:

The increased crude oil production is being driven by activity in the Barnett and Eagle Ford Shale plays in Texas and the Bakken shale formation in North Dakota. The Texas Railroad Commission released its updated production statistics for December 2012, noting that 51.1 million barrels of crude oil (nearly one quarter of the nation's output) were produced on onshore Texas fields. This statistic does not include output from the oil rich Gulf of Mexico fields.

Originally established to regulate Texas’ railroads, the Commission is now responsible for regulating oil and gas production in the State of Texas.