At the height of his phenomenal success and fame, after his song “A Horse with No Name” had galloped to the top of the Billboard Hot 100 and the band he co-founded, America, had won best new artist at the 1973 Grammy Awards, Dewey Bunnell quietly settled down in Marin County, living the life of a young family man who just so happened to be one of the world’s biggest rock stars.

While his partner and bandmate, Gerry Beckley, held court in a party pad above L.A.’s Sunset Strip and hung out with the likes of David Bowie and the Beach Boys, Bunnell and his wife, Vivien, his high school sweetheart, bought a house in San Anselmo and raised their two children, a boy and a girl, becoming part of the Marin community.

“I’d always tried to hang on to stability, trying to keep my feet on the ground,” said Bunnell during a phone interview last week. “I wanted to have a home to come back to that wasn’t a transient thing.”

Despite their divergent lifestyles, Bunnell and Beckley endured as partners and bandmates for five decades. That journey is chronicled in a new documentary, “I Need You: 53 Years of the Band America,” which follows these two surviving members on their last tour together in 2023. It screens at 6 p.m. May 3 at the Smith Rafael Film Center in San Rafael as part of the California Film Institute’s DocLands Documentary Film Festival. Get tickets ($25 to $45) at doclands.com/film/i-need-you-53-years-of-the-band-america.

Directors David Breschel and Dustin Elm began shooting the documentary for no other reason than to honor the band’s legacy, revisiting its remarkable parade of ’70s and early ’80s hits: “A Horse with No Name,” “I Need You,” “Ventura Highway,” “Sister Golden Hair,” “Tin Man,” “Lonely People” and “You Can Do Magic.”

Just when they had finished a rough cut of the documentary, the filmmakers were told that Beckley, at 72, had decided to retire from touring and that the 2023 tour would be his last. After performing 5,000 shows — about 100 a year — since America first formed in England in 1970, he wanted to be at home with his family, splitting his time between Australia, where his wife, his third, is from, and his house in Venice, the Southern California beach town.

With Beckley’s announcement, the filmmakers, who had already shot the first half of the 2023 tour, went back out on the road with the band for the final two weeks, counting down to the duo’s final show together.

“It drastically changed things,” Breschel said. “As filmmakers, it was a blessing. We were happy with the movie before that component, but it made it something special.”

The documentary ends with the band on “hiatus” with its future very much in doubt. “We purposely left it with the two of them alone at home, leaving you to wonder which one of them was going to get bored with this new lifestyle first,” Breschel said.

He was surprised when it turned out to be Bunnell, who’s 73 and now lives in the Temecula-Murrieta area of San Bernardino County in Southern California with his second wife, Penny, of 23 years. After five months at home, he became “itchy” to tour and perform again for live audiences.

“People have said to me since the beginning, ‘How can you get up there and do ‘Horse with No Name’ every night?’” he said. “On paper, it looks like you could do it in your sleep. But there’s a whole other element of having a live audience and a different sound every night in a different hall with a different atmosphere. It’s its own live organic thing. And in this day and age, when everything seems to be virtual, that’s what I was missing. I was missing that flesh and blood live experience.”

Encouraged by the band’s agent, who had numerous offers to book America going forward, Bunnell called his longtime partner and got his blessing to keep America going with him as the last original member.

“People online say it isn’t the same without Gerry, and I concur,” he said. “But there are numerous classic rock bands out there that are performing with as little as one member, myself being one of them. Some bands don’t have any original members. What does that say? It says people come for the music. I always say that, too. The music lasts forever.”

Moving to Marin

Bunnell, Beckley and their late bandmate, Dan Peek, who died in 2011, met as teenagers when their fathers were stationed in London with the Air Force. They were just out of high school when their self-titled debut album, released in 1971, made them overnight sensations on the strength of their pipe organ harmonies and folk-rock sound on Bunnell’s enigmatic horse song, a runaway hit, and Beckley’s now-classic ballad “I Need You.”

Bunnell moved to Marin after America recorded its third album, 1973’s “Hat Trick,” at the Record Plant in Sausalito with producer George Martin, the famed producer of the Beatles.

“I’d never been to Marin County, but we fell in love with the place and decided to get out of L.A.,” said Bunnell, saying he had never felt at home in the Los Angeles sprawl and liked Marin’s proximity to San Francisco. “San Francisco had more of a cosmopolitan feel. We had lived in London and it felt more compatible.”

During his 27 years in Marin, Bunnell collected art, focusing on the Bay Area figurative movement. He invested as a silent partner in the San Rafael Station Café and palled around with the Grateful Dead’s Phil Lesh, who met his wife at the restaurant.

Bunnell was part of an era when rock stars were as common as redwood trees in Marin. He got to know the members of Journey and is still in touch with singer Steve Perry. Huey Lewis, another friend, lived nearby in Ross. During that time, Uncle Charlie’s, a now-defunct nightclub in Corte Madera, was a hot spot on the Marin music scene. Bunnell took in lots of shows there, but was never one to sit-in with anyone else’s band. He may have been Marin’s most under-the-radar celebrity rocker.

“I’m not that kind of musician. I’m insecure,” he said. “I’m better with my own music and watching everybody else do theirs. Gerry Beckley, my partner, is well versed musically and will sit-in with people now and then, but I don’t trust myself up there. I liked seeing those guys perform and getting to know them and learning Marin’s music history as well.”

Bunnell’s son, Dylan, and daughter, Lauren, graduated from St. Mark’s School — now Mark Day School — in San Rafael and Marin Catholic High School, where Dylan was a star football player. Bunnell and America played benefit concerts for both schools when his kids were students there.

Then and now, America was in demand as a touring concert act. Bunnell was often gone for weeks and months at a time. The documentary makes a point of showing the grind of life on the road.

“I fit into that same category of absent fathers in the sense that I was always coming and going,” he said. “The suitcase was rarely unpacked. I like to think I managed to be a part of my kids’ school years and field trips, to do what I could when I was home, but a lot of time I wasn’t there. It was a reunion-and-goodbye-type of family situation. My wife took good care of everything in my absence.”

With the end of his marriage in 1999, Bunnell returned to Los Angeles, living in Palos Verdes, and remarried three years later. He has three grandchildren.

Last summer, he returned to the road with a four-piece band that included singer-guitarist Andy Barr, who had performed with America in the past, replacing Beckley. On the band’s 55th anniversary this year, Bunnell and the same lineup are booked through November, playing mostly theaters and regional performing arts centers on what is being billed as “The Encore Tour.”

“I never committed emotionally to retirement,” he said. “I may have committed on paper. We were getting tired, we didn’t have any new material and we had been doing this for 50-plus years. But there’s an element, an intangible, and that’s performing live. Underneath it all, that’s what I must have been craving because I really do want to play. And that’s what I’m still doing.”

Contact Paul Liberatore at p.liberatore@comcast.net