The number of rigs actively exploring for oil and natural gas in the U.S. increased by 12 this week to 1,920.

Houston-based drilling product provider Baker Hughes Inc. reported Friday that 1,031 rigs were exploring for oil and 883 for natural gas. Six were listed as miscellaneous. A year ago this week the rig count stood at 1,605.

Of the major oil- and gas-producing states, Oklahoma gained nine rigs, North Dakota gained five, Texas gained four, New Mexico gained two and California and Pennsylvania each gained one. Louisiana and Wyoming each lost three rigs and Arkansas, Colorado and West Virginia each lost one. Alaska was unchanged.

The rig count peaked at 4,530 in 1981. A low of 488 was recorded in 1999.