The number of rigs exploring for oil and natural gas in the U.S. declined by three this week to 421, snapping three weeks of gains after a slide that lasted months and pushed the count to record-low levels amid depressed energy prices.

A year ago, 859 rigs were active.

Houston oilfield services company Baker Hughes Inc. said Friday 330 rigs sought oil and 90 explored for natural gas. One was listed as miscellaneous.

Among major oil- and gas-producing states, Texas gained three rigs, North Dakota two and Alaska and Colorado, one each.

Louisiana declined by five, Oklahoma four and West Virginia one.

Arkansas, California, Kansas, New Mexico, Ohio, Pennsylvania, Utah and Wyoming were unchanged.

The U.S. rig count bottomed out last month at 404.