HOUSTON (AP) — The number of rigs actively exploring for oil and natural gas in the U.S. is unchanged this week, holding at 1,979.

Houston-based oilfield services company Baker Hughes Inc. reported Thursday that 1,329 rigs were exploring for oil and 647 for natural gas. Three were listed as miscellaneous. A year ago this week Baker Hughes reported 1,782 active rigs.

Of the major oil- and gas-producing states, Oklahoma gained four rigs. Alaska, New Mexico and Pennsylvania picked up two apiece. Texas gained one.

West Virginia lost six rigs, while Colorado and Louisiana dropped two each. North Dakota was down one.

Arkansas, California and Wyoming were unchanged.

The rig count peaked at 4,530 in 1981 and bottomed at 488 in 1999.