Beaver is a stage, film, and television actor, a playwright, screenwriter, and film historian. He is most familiar to worldwide audiences as the gruff but tenderhearted prospector Whitney Ellsworth on David Milch's HBO Western drama series Deadwood, a starring role which brought him acclaim and a Screen Actors Guild Awards nomination for Ensemble Acting after three decades of supporting work in films and TV.
Jim Beaver made his professional stage debut in October, 1972, while still a college student, in Rain, by W. Somerset Maugham at the Oklahoma Theatre Center in Oklahoma City. After returning to Texas, he did a great deal of local theatre in the Dallas area, supporting himself as a film cleaner at a 16mm film rental firm and as a stagehand for the Dallas Ballet. He joined the Shakespeare Festival of Dallas in 1976, performing in numerous productions. In 1979, he was commissioned by Actors Theatre of Louisville to write the first of three plays for that company (Spades, Sidekick, and Semper Fi), and was twice a finalist in the theatre's national Great American Play Contest (for Once Upon a Single Bound and Verdigris). Along with plays, he continued writing for film journals and for several years was a columnist, critic, and feature writer for the National Board of Review of Motion Pictures magazine Films in Review.
Moving to New York City in 1979, Beaver worked steadily onstage in stock and on tour, simultaneously writing plays and researching a biography of actor George Reeves (a project which he still pursues between acting jobs).
In 1983, he moved to Los Angeles to continue research on his biography of Reeves. He worked for a year as the film archivist for the Variety Arts Center. Following a reading of his play Verdigris, he was asked to join the prestigious Theatre West company in Hollywood, where he continues as an actor and playwright to this day. Verdigris was produced to very good reviews in 1985 and Beaver was signed by the powerful Triad Artists agency. He immediately began to work writing episodes of various television series, including Alfred Hitchcock Presents, Tour of Duty, and Vietnam War Story. He also worked occasionally in small roles in films and television.
The 1988 Writers Guild of America strike fundamentally altered the freelance television writing market, and Beaver's TV writing career came to an abrupt halt. However, a chance meeting led to his being cast as the best friend of star Bruce Willis in Norman Jewison's drama about Vietnam veterans, In Country, and his acting career suddenly took up the slack where his TV writing career had faltered. (Beaver was the only actual Vietnam veteran among the principal cast of In Country.)
Subsequently he has appeared in many popular films, including Sister Act, Sliver, Bad Girls, Adaptation., and Magnolia. He starred in the TV series Thunder Alley as the comic sidekick to Ed Asner, and as homicide cop Earl Gaddis on Reasonable Doubts.
In 2002, Beaver was cast as one of the stars of the ensemble Western drama Deadwood in the role of goldminer Whitney Ellsworth. Ellsworth went from being a filth-covered reprobate to marrying the richest woman in town and becoming a beloved and stalwart figure in the community. (Trivia note: Originally Ellsworth did not have a first name, but when it became necessary to provide one, Beaver requested he be named Whitney Ellsworth, after the producer of George Reeves's Adventures of Superman.) He continued his long research for the Reeves biography, and in 2005 served as the historical/biographical consultant on the theatrical feature film about Reeves's death, Hollywoodland.
Beaver recently joined the cast of the HBO drama John from Cincinnati while simultaneously playing the recurring role of Bobby Singer on Supernatural.