Robert Redford, the actor-director who founded the Sundance Institute and the Sundance Film Festival, reshaped the American film landscape by creating a sustained platform for independent filmmakers, supporters and colleagues said after his death Tuesday at age 89.

Dismayed by what he saw as the limits of mainstream Hollywood, Redford spent decades building a year-round organization and an annual festival in Park City, Utah, that prioritized independent vision and helped launch the careers of a generation of directors, writers and producers. He remained the founder and president of the institute until his death, though he stepped back from many public duties in 2019.

Redford’s interest in Utah began on a 1961 motorcycle trip and grew into a multi-thousand-acre property he named Sundance after his character in Butch Cassidy and the Sundance Kid. In 1981, after winning the Academy Award for Ordinary People, he established the nonpartisan Sundance Institute and staged the first filmmaker labs at his Sundance Mountain Resort. The institute took control of the U.S. Film Festival in 1985; it was later renamed the Sundance Film Festival and became the best-known showcase for new independent features and documentaries.

Over four decades, the institute’s labs and the festival’s screening programs gave early exposure to filmmakers who would become major figures in the industry. Early discoveries included Steven Soderbergh’s Sex, Lies, and Videotape, which premiered in Park City in 1989 and helped spark an independent film boom. Subsequent Sundance debuts included films such as Quentin Tarantino’s Reservoir Dogs, Richard Linklater’s Slacker, the Coen brothers’ Blood Simple, Jim Jarmusch’s Stranger Than Paradise, Wes Anderson’s Bottle Rocket and Richard Linklater’s Before Sunrise. More recent alumni include Ryan Coogler, Chloé Zhao, Taika Waititi, Ava DuVernay, Paul Thomas Anderson, Rian Johnson, Gina Prince-Bythewood, Daniel Kwan and Daniel Scheinert.

Redford framed the effort in explicit terms: ‘‘For me, the word to be underscored is ‘independence,’’’ he told The Associated Press in 2018. He said he wanted to create a category that supported artists ‘‘who weren’t given a chance to be heard.’’ Sundance’s programs, festival leaders and many filmmakers say that mission guided both the public event in Park City and the quieter, year-round work at the institute.

The institute’s writer and director labs, developed under longtime lab chief Michelle Satter, provided hands-on mentorship that has directly influenced first films and helped shepherd projects from script to screen. Filmmakers and lab advisers have credited the labs with creating communities in which early projects could be shaped and financed; credits linked to Sundance programs have included films such as Hard Eight, Fruitvale Station, Love & Basketball and No Other Land, among others.

The festival also made a point of expanding representation. In 1994 the Sundance Institute launched a program to highlight Native and Indigenous films, a commitment that continues. Indigenous filmmaker Sterlin Harjo said support from Sundance as a young participant ‘‘made me feel like I belonged in an industry that most times felt so unreachable.’’

Sundance screenings have led to wider acclaim and awards for many films that first played in Park City. CODA, which played the festival in 2021, later won the Academy Award for best picture. Documentaries that began life at Sundance and went on to win Oscars include When We Were Kings, Born Into Brothels, An Inconvenient Truth, Man on Wire, The Cove, Searching for Sugarman, 20 Feet From Stardom, Icarus, American Factory and Navalny. The festival has also been the launching pad for commercially and critically successful narrative films such as Get Out, Whiplash, Little Miss Sunshine, Memento, Boyhood and Call Me By Your Name.

Attendance at the festival grew dramatically over the decades, from an estimated 15,504 attendees in 1996 to a peak reported in 2018 of roughly 124,900. Numbers have fluctuated since; the festival estimated about 85,472 in-person attendees for the 2025 edition, an increase from the year before. Festival leaders said in 2025 that the event would relocate from Park City to Boulder, Colorado, beginning in 2027, marking a major logistical and symbolic shift for an event that was long associated with Utah’s mountains and the creative community Redford fostered there.

Leaders at the Sundance Institute said Redford’s vision ‘‘launched a movement that, over four decades later, has inspired generations of artists and redefined cinema in the U.S. and around the world.’’ Former festival director John Cooper, who led Sundance from 2009 to 2020 and remained a close friend and ally, said his role had been to ‘‘be a keeper of the flame for Robert Redford and his legacy.’’ Cooper added that preserving and extending that legacy — focused on the power of storytelling and on giving new voices access to the industry — would be a central task for those who run the institute and festival going forward.

Redford’s supporters point to both the festival’s high-profile premieres and the institute’s quiet, sustained mentorship as the twin engines of his impact. Filmmakers and executives credit the annual festival with creating a market and an audience for films that might otherwise never have found distribution, while the labs provided practical and creative guidance that helped many projects reach their first screens.

Plans to celebrate Redford’s contributions were already under way within the institute and among the festival’s community. With his death, the tributes and retrospectives are likely to take on greater emphasis at forthcoming editions of the festival and in the institute’s year-round programs, as colleagues and alumni reflect on the ways a single institution altered the course of contemporary independent cinema.