The number of rigs exploring for oil and natural gas in the U.S. rose by 10 this week to 857. Louisiana's count was unchanged, but up 11 from a year ago.

A year ago, 431 rigs were active in the U.S. The U.S. rig count bottomed out last May at 404.

Houston oilfield services company Baker Hughes Inc. said Friday that 688 rigs sought oil and 167 explored for natural gas this week. Two were listed as miscellaneous.

Texas added six rigs and Alaska, Colorado, North Dakota, Pennsylvania and Wyoming each gained one.

Oklahoma lost one rig.

Arkansas, California, Kansas, New Mexico, Ohio, Utah and West Virginia were unchanged.