Treat Williams, the actor known for his roles in the movies “Hair” and “Deep Rising” and the TV show “Everwood,” has died. He was 71.

Mr. Williams died on Monday after an S.U.V. crashed into his motorcycle in Dorset, Vt., the Vermont State Police said in a statement.

The crash occurred in the late afternoon near the Vermont-New York State border.

The Vermont State Police said that a southbound S.U.V. attempting to turn left into a parking lot drove into the path of Mr. Williams’s northbound Honda motorcycle, adding that Mr. Williams was “unable to avoid a collision and was thrown from his motorcycle.”

Mr. Williams, who was wearing a helmet at the time of the accident, suffered critical injuries and was pronounced dead at a medical center in Albany, N.Y., after being airlifted there, the state police said. The 35-year-old man whose vehicle hit Mr. Williams was not hospitalized.

The police said an investigation was underway. No other details were immediately available.

Richard Treat Williams was born in Stamford, Conn., in 1951. “Treat” is a Welsh name that has been in his family for generations.

Mr. Williams moved with his family to Rowayton, Conn., as a young child, he told Vermont Magazine in a 2021 interview. His father was a World War II veteran who later worked for the Merck pharmaceutical company. His mother owned a sailing and swimming school on Long Island Sound.

“Looking back on my younger years, I had an idyllic childhood, but I didn’t initially realize how idyllic it truly was until I grew older,” he told the magazine.

Mr. Williams began acting in seventh grade, he told Vermont Magazine. Later, at Franklin and Marshall College in Pennsylvania, he quit the football team to focus on acting.

Within a few years, he was on Broadway as the understudy to four of the male leads in “Grease,” including John Travolta. Then he began picking up roles in films starring James Earl Jones, Michael Caine and other A-list stars. One of his highest-profile roles was playing a hippie in the 1979 film version of “Hair,” directed by Milos Foreman.

But his success wasn’t always assured. After a movie he starred in flopped in 1980 — the comedy “Why Would I Lie?” — Mr. Williams started flying planes for a company in Los Angeles.

“I’d done eight films, none of which had been successful,” he told The New York Times in 1981. “I felt so out of control. I wasn’t working with people I wanted to work with. I was very frustrated.”

Mr. Williams eventually came back to show business and racked up four more decades of roles in a wide variety of film and television projects.

Among other highlights, he played the lead roles of a police officer-turned-informant in the 1981 film “Prince of the City” and a boat captain in the 1998 action movie “Deep Rising.”

He also starred in “Everwood,” a WB television series about a New York neurosurgeon who starts a new life with his family in the mountains of Colorado after his wife dies in a car accident. The show debuted in 2002 and ran for four seasons.

More recently, Mr. Williams played the impossibly single old flame of a woman who tries to sell her hometown in the 2020 Netflix musical “Dolly Parton’s Christmas on the Square.” He also played a retired detective in the 2022 HBO series “We Own This City.”

Information about Mr. Williams’s survivors was not immediately available.

Hours before he died, Mr. Williams, who lived in Manchester Center, Vt., posted a photo on Twitter that he appeared to have taken from the seat of his lawn mower.

“Mowing today,” he wrote. “Wish I could bottle the scent.”

Jesus Jiménez contributed reporting.