Dan Haggerty, who played a gentle mountain man with a luxuriant beard and a bear named Ben in the 1974 movie “The Life and Times of Grizzly Adams” and the NBC television series of the same name, died on Friday in Burbank, Calif.

He was 73.

The cause was cancer of the spine, his friend and manager Terry Bomar said.

Mr. Haggerty was working as a stuntman and animal handler in Hollywood when a producer asked him to act in some opening scenes he was reshooting for a film about a woodsman and his bear.

Based on the novel “The Life and Times of Grizzly Adams,” by Charles Sellier Jr., it told the story of a California man falsely accused of murder who flees to the woods, where he develops a rapport with the animals around him and tames an orphaned bear.

Mr. Haggerty agreed, but only if he could do the entire movie. The film was remade for $165,000 and eventually took in nearly $30 million at the box office. It was then adapted for television, and in February 1977 Mr. Haggerty resumed his eco-friendly role as guardian of the woods and friend to the animals.

“It lukewarms the heart,” John Leonard wrote a review of the first episode in The New York Times. “Man and bear hide out in a log cabin, to which Mad Jack (Denver Pyle) and the noble red man Makuma (Don Shanks) bring flour and advice. When they leave the cabin, man traps fur while bear washes his. Meanwhile, there are raccoons, owls, deer, rabbits, hawks, badgers, cougars, a lot of communing with nature and a big lump in the throat.”

Genial and sentimental, the series endeared Mr. Haggerty to viewers and made him the winner of a People’s Choice Award in 1978 as the most popular actor in a new series. “Grizzly Adams” spawned two codas: “Legend of the Wild,” broadcast in 1978 and released theatrically in 1981, and “The Capture of Grizzly Adams,” broadcast as a TV movie in 1982, in which Adams is taken back to town by bounty hunters and finally clears his name.

Daniel Francis Haggerty was born on Nov. 19, 1942, in Los Angeles. His parents separated when he was 3, and he had a troubled childhood, escaping several times from military school before going to live with his father, an actor, in Burbank, Calif.

At 17 he married Diane Rooker. The marriage ended in divorce. His second wife, the former Samantha Hilton, died after a motorcycle accident in 2008. He is survived by his children, Megan, Tracy, Dylan, Cody and Don.

His first film was “Muscle Beach Party” (1964), in which he played a body builder named Biff opposite Frankie Avalon and Annette Funicello. Bit parts in biker and wildlife films followed, as characters like “Bearded Biker” or “Biker With Bandana.” He appeared briefly in “Easy Rider” as a member of the hippie commune that Peter Fonda and Dennis Hopper visit.

In real life, Mr. Haggerty lived on a small ranch in Malibu Canyon with an assortment of wild animals that he had tamed at birth or rescued from injury. His skills led to jobs as an animal trainer and stuntman on the television series “Tarzan” and “Daktari,” as well as occasional film work. “Actors didn’t like animals leaping on them,” he told People magazine in 1978.

He made several films with an outdoor setting, including “Where the North Wind Blows” (1974), in which he played a Siberian tiger trapper, and “The Adventures of Frontier Fremont” (1976). He appeared as a dog trainer in the David Carradine film “Americana” (1983). In “Grizzly Mountain” (1997) and “Escape to Grizzly Mountain” (2000) he played a character very much like Grizzly Adams.

As his career cooled, Mr. Haggerty appeared in horror films like “Terror Night” (1987), “Elves” (1989) — playing an alcoholic mall Santa — and “Axe Giant: The Wrath of Paul Bunyan” (2013). In 1985 he was sentenced to 90 days in jail for selling cocaine to two undercover police officers.

In 1977, a careless restaurant patron carrying a flaming cocktail set Mr. Haggerty’s famous beard on fire. Trying to extinguish the flames, he suffered third-degree burns on his arms and was taken to a hospital for treatment that was expected to last a month.

“The first couple of days I just lay in the dark room drinking water, like a wounded wolf trying to heal himself,” he told People. “Nurses tried to give me morphine and encouraged me to open the curtains. But sometimes animals know more than people about healing.” He walked out of the hospital after 10 days.