An inmate serving time for conspiracy to distribute PCP and possession of a firearm walked away from the minimum security Federal Correctional Complex in Lompoc on Thursday, according to the Federal Bureau of Prisons.

At about 1 p.m., prison guards discovered Carl Henderson, 47, was missing. Prison officials notified the U.S. Marshals Service and other law enforcement agencies, but authorities have yet to locate Henderson.

Henderson, who was serving a sentence of more than 17 years, is 5 feet 11 inches tall and 170 pounds. He has brown eyes and black hair.

The minimum security facility, also known as a satellite camp, is adjacent to the medium security federal penitentiary in Lompoc. In recent years, inmates have frequently walked away from the Lompoc prison camp.

At least seven inmates escaped the camp in 2016. It is unclear how many of the fugitives have been apprehended.