The number of rigs exploring for oil and natural gas in the United States decreased by four this week to a total of 1,778.

Oilfield services company Baker Hughes Inc. says in its weekly report Friday that 1,385 rigs were exploring for oil and 386 for gas.

Seven were listed as miscellaneous. A year ago there were 1,931 active rigs.

Of the major oil- and gas-producing states, Colorado gained three rigs and Kansas and North Dakota each gained one.

California lost four rigs, New Mexico and Texas each lost two and Alaska and Wyoming each lost one. Arkansas, Louisiana, Ohio, Oklahoma, Pennsylvania, Utah and West Virginia were unchanged.

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