The number of rigs actively exploring for oil and natural gas in the U.S. fell by six this week to 1,987.

Houston-based drilling product provider Baker Hughes Inc. reported Friday that 1,161 rigs were exploring for oil and 820 for natural gas. Six were listed as miscellaneous. A year ago this week Baker Hughes reported 1,723 active rigs.

Of the major oil- and gas-producing states, Colorado picked up four rigs and California and West Virginia each gained three.

Alaska, Texas and Wyoming picked up one apiece.

Louisiana lost 10 rigs, and North Dakota dropped three. Oklahoma and Pennsylvania fell by two each. Arkansas was down by one.

New Mexico was unchanged.

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