Oilfield services company Baker Hughes Inc. says the number of rigs exploring for oil and natural gas in the U.S. this week declined by four to 838.

Houston-based Baker Hughes said Friday that 640 rigs were seeking oil, 197 explored for natural gas and one was listed as miscellaneous. A year ago, with oil prices about double the prices now, 1,931 rigs were active.

Among major oil- and gas-producing states, New Mexico gained one rig. Texas lost two rigs in this week’s tally, while Arkansas, North Dakota and Oklahoma each lost one rig.

The rig counts for Alaska, California, Colorado, Kansas, Louisiana, Ohio, Pennsylvania, Utah, West Virginia and Wyoming were unchanged.