Best known for his roles as Bobby Singer on the CW thriller Supernatural and as David Milch on the HBO western Deadwood. He has also had recurring roles on such series as Justified and Harper's Island.
He joined the U.S. Marine Corps after high school. He first appeared on television in a 1978 episode of the popular soap opera Dallas.
He published a memoir entitled Life's That Way in 2009.
He was married to his second wife, actress Cecily Adams, from 1989 until her death in 2004. Together they had a daughter, Madeline, who was born in 2001. His first wife was Debbie Young.
He played a role opposite Nicolas Cage in the 2002 film Adaptation.