Charles Siebert, the stage-trained actor who portrayed the snooty Dr. Stanley Riverside II on all seven seasons of the CBS drama Trapper John, M.D., has died. He was 84.

Siebert died May 1 of COVID-related pneumonia at University of California San Francisco Medical Center, his daughter, Gillian Bozanic, told The Hollywood Reporter.

On the big screen, the accomplished Siebert showed up in such films as The Other Side of Midnight (1977), Blue Sunshine (1977), Coma (1978), Norman Jewison’s … And Justice for All (1979), All Night Long (1981), White Water Summer (1987) and Eight Men Out (1988).

Siebert played Helen Keller’s father in the 1979 NBC telefilm The Miracle Worker that starred Melissa Gilbert as Helen and Patty Duke — an Oscar winner 16 years earlier for her turn as the blind, deaf and mute girl — as teacher Annie Sullivan.

Siebert appeared on all 151 episodes of the MASH spinoff Trapper John, which aired from 1979-86. His character, the head of emergency services at San Francisco Memorial Hospital, often clashed with surgeon “Trapper” John McIntyre, played by Pernell Roberts.

He became a TV director on the Fox Television series in 1982 and went on to helm episodes of such other shows as Knots Landing, Pacific Blue, Silk Stalkings, Pensacola: Wings of Gold, Hercules: The Legendary Journeys and Xena: Warrior Princess through 2001.

Charles Alan Siebert was born on March 9, 1938, in Kenosha, Wisconsin. He studied acting at Marquette University under the renowned Father John J. Walsh and at the London Academy of Music and Dramatic Art, then became a charter member of San Francisco’s American Conservatory Theater in 1965 alongside Richard Dysart, Michael Learned and others.

Siebert appeared on Broadway in Bertolt Brecht’s Galileo in 1967, in Jimmy Shine opposite Dustin Hoffman in 1968-69 and in Neil Simon‘s The Gingerbread Lady alongside Maureen Stapleton in 1970-71, then worked for Joseph Papp in a Public Theater production of David Rabe’s Sticks and Bones in 1971.

Meanwhile, he was making ends meet with roles on such daytime soap operas as Search for Tomorrow, As the World Turns and Another World. He headed to Los Angeles in the mid-1970s.

In 1987, Siebert was cast alongside Hayley Mills as her husband on the NBC pilot Good Morning, Miss Bliss; when the show — to eventually become Saved by the Bell — was picked up by the Disney Channel, his role was discarded.

His stage résumé also included David Storey’s The Changing Room and Tennessee Williams’ Cat on a Hot Tin Roof on Broadway and Rubbers, directed by Alan Arkin, off-Broadway.

He spent seven summers at the Williamstown Theatre Festival in Massachusetts.

Siebert recurred as the boss of Bonnie Franklin‘s character on CBS’ One Day at a Time from 1977-79 and starred on the short-lived Joan Rivers-created comedy Husbands, Wives & Lovers, also for CBS, in 1979.

He guest-starred three times on All in the Family and appeared on other shows including N.Y.P.D., Kojak, Police Woman, The Rockford Files, The Incredible Hulk, Maude, Mancuso, FBI and Murder, She Wrote.

Survivors include his second wife, Kristine, whom he married in 1986; children Gillian and Christopher, a musician with the band Lavay Smith and Her Red Hot Skillet Lickers; step-children Kristina, Max and Jeremy; and brothers Ronald, Leonard and Jack.

His first wife, Catherine, died in 1981 of breast cancer at age 44. Another son, Charlie Jr., died in 2020.

Siebert moved to Sonoma County in 1992 and continued to act and direct on stages in the area.

“Charlie was never one to over-compliment, or gush, or flatter,” Craig A. Miller, former artistic director of the 6th Street Playhouse in Santa Rosa, wrote in a tribute to the actor. “He was serious about his craft; he worked hard, and he expected everyone around him to do the same. He lifted us all to a new level of theatricality and magic. As an actor, he didn’t want the praise — he wanted the damn notes.”

Contributions in his name may be made to Doctors Without Borders or World Central Kitchen, two of his favorite organizations.