Oilfield services company Baker Hughes Inc. says the number of rigs exploring for oil and natural gas in the U.S. declined by nine this week to 859.

Houston-based Baker Hughes said Friday 635 rigs were seeking oil and 221 explored for natural gas. Three were listed as miscellaneous. A year ago, with oil prices nearly double the current levels, 1,854 rigs were active.

Among major oil- and gas-producing states, Alaska, Colorado, Kansas, New Mexico, Ohio, Texas, Utah and West Virginia each declined by one rig.

Louisiana and Oklahoma both gained one rig apiece.

Arkansas, California, North Dakota, Pennsylvania and Wyoming were unchanged.