HOUSTON -- Wyoming gained one rig actively exploring for oil and natural gas this week, while the national number of rigs dropped by 43 this week to 1,721.

Houston-based Baker Hughes Incorporated reports today that of the rigs running nationwide, 1,347 were exploring for natural gas and 364 for oil. A total of ten were listed as miscellaneous.

A year ago, the rig count stood at 1,782.

Of the major oil- and gas-producing states, Texas lost 23 rigs, Oklahoma lost six, Colorado lost three, Arkansas lost two, and North Dakota and California each lost one. Wyoming and Louisiana each gained one rig. Alaska was unchanged. New Mexico added two rigs.

Baker Hughes has tracked rig counts since 1944. The tally peaked at 4,530 in 1981, during the height of the oil boom. The industry posted several record lows in 1999, bottoming out at 488.