Bruce Baillie, an experimental filmmaker who turned wind-swept grass, belching smokestacks and a weathered picket fence into visual poetry, exploring the natural world and indigenous cultures in works that placed him at the forefront of cinema’s 1960s avant-garde, died April 10 at his home on Camano Island, Wash. He was 88.

He had Alzheimer’s disease, said his wife, Lorie Baillie.

Mr. Baillie’s films never received wide theatrical release, were often only a few minutes long and typically featured no conventional plot or characters. Yet through their technical innovations, sensuous beauty and Zen-like meditations on nature, mortality and the destruction of the environment, they made Mr. Baillie a key influence on independent filmmakers such as Thai director Apichatpong Weerasethakul.

They also made Mr. Baillie a cornerstone of the West Coast underground film scene, which he helped galvanize during a career spent mainly in the Bay Area. While living in the hills overlooking Oakland, Calif., in the early 1960s, he worked at a Safeway to pay for 16-millimeter film and equipment, including a projector and Army-surplus screen that he used to project films from his kitchen window.

Early screenings — before an audience that included a teenage George Lucas, then in thrall to abstract, experimental films — featured works by avant-garde filmmakers such as Jonas Mekas, Stan Brakhage and Larry Jordan, served with free wine and popcorn. Mr. Baillie later joined with Chick Strand to found the nonprofit San Francisco Cinematheque, building a home for like-minded filmmakers who viewed cinema as an art form that could stand alongside painting, literature and music.

For his part, Mr. Baillie honed a style that combined a documentary approach with a deeply personal vision, developing what Mekas once called “the most fluid, lyrical-pastoral film language that I know.” Praising Mr. Baillie and director Carroll Ballard in a 1966 essay, movie critic Pauline Kael wrote that their “camera skills expose how inept, inefficient, and unimaginative much of Hollywood’s self-praised work is.”

Mr. Baillie initially made concentrated, haiku-like shorts such as “Mr. Hayashi” (1961), a three-minute portrait of a gardener, before demonstrating a more expansive, semi-narrative approach in works such as “Quick Billy” (1971). An hour-long reflection on mortality, the film was set to a score by composer John Adams and inspired by the Tibetan Book of the Dead as well as Mr. Baillie’s near-fatal struggle with hepatitis.

“He made movies that were very much invested in the real world around him, primarily the world of nature, but he would craft those images into very eloquent and articulate artworks that bore his stamp at every moment,” film scholar David Sterritt said by phone. Mr. Baillie, he added, was “ahead of the game” in exploring “the different ethnicities, different cultures, that are all part of the great American canvas writ large,” notably through his films “Mass for the Dakota Sioux” (1964) and “Valentin de las Sierras” (1968).

Working by hand in the editing room (like Brakhage, he preferred the term “composing” instead of “editing”), Mr. Baillie layered multiple images onto the screen in works such as “Castro Street” (1966), which combined color and black-and-white sequences to bring an industrial section of Richmond, Calif., to nightmarish life, intercutting shots of an oil refinery and rail yard with images of tall flowers and grass.

“Mr. Baillie creates a film that represents less the world as it seems to exist than one that’s been refracted through his being,” New York Times critic Manohla Dargis wrote in 2016. “As he pours on the color, mixes in the chugs and clangs, evokes the Brothers Lumière and swings between the figurative and the abstract, the line between place and head space dissolves and a portrait of the artist emerges — brilliantly.”

“Castro Street” was selected for the National Film Registry in 1992 and is screened regularly in New York City as part of Anthology Film Archives’ Essential Cinema collection, which aims to “define the art of cinema.” The center has also highlighted five other Baillie works in its repertory collection, including “All My Life,” a three-minute short that marks one of Mr. Baillie’s most lyrical and moving efforts.

The film consists of a single panning shot, showing a picket fence framed by the sky and summer grass. As Mr. Baillie slowly moves the camera from right to left, Ella Fitzgerald and pianist Teddy Wilson’s recording of “All My Life” plays on the soundtrack, finishing just as Mr. Baillie tilts the camera upward — hesitating for a moment before passing an electrical wire and settling on the clear blue sky.

“It’s as if you’re passing into eternity but pausing just one moment as there’s this last remnant of the material world,” Sterritt said. “It’s one of the glorious moments in avant-garde film. I still use it in teaching to this day.”

Bruce Carlyle Baillie was born in Aberdeen, S.D., on Sept. 24, 1931. While his father taught sculpture, Mr. Baillie said his artistic leanings were initially toward drama. After he and a few friends got into trouble, they were tasked with putting on a play for a school assembly. “At first, we thought this was a severe penalty,” Mr. Baillie told film scholar Scott MacDonald in 1989, “but pretty soon we liked the idea.”

Mr. Baillie served in the Navy during the Korean War and studied at the University of Minnesota, where a professor suggested he attend the London School of Film Technique. England proved a disappointment — he dropped out within a year, dismayed by the quality of the instruction as well as the “London fog and the poor food” — but he found inspiration after traveling to Zagreb, then in Yugoslavia.

At a well in the center of town he saw an intricate sculpture, showing a group of people, young and old, passing through the ­stages of life. “I thought, ‘This relief is at the source; it’s an essential part of everyday life,’ ” Mr. Baillie told MacDonald. “I liked that, and decided I wanted to do something similar with film.”

He had never used a still camera, let alone synced sound and images, but apprenticed under a travel filmmaker and in 1961 made his first serious film. “For quite some time,” he said, “I was like a gymnast without any grace.” But he continued working and soon fell into a groove, making movies that were inspired less by the work of other filmmakers than by Indian raga music or the weather.

He said he spent three days admiring the summer light in Casper, on the northern California coast, before deciding to film a picket fence there for “All My Life.” Only after starting his drive back to San Francisco did he realize that the fence should serve as a film subject — “No, I cannot turn my back on this!” — and turn around to get the shot he wanted. The end result, Dargis wrote, was “one of the most perfect films that I’ve ever seen.”

Mr. Baillie married Lorie Apit in 1986 and later settled on Camano Island, in a house his parents had owned. They had made his films possible, he said, offering financial support and a roof over his head at a time when “poverty was really the mother or the sister of our craft and of our lives.”

In addition to his wife, survivors include two children, Keith and Wind Baillie.

Partly funded by Lucas’s charitable foundation, Mr. Baillie had digitally transferred his film archives in recent years, working to preserve a body of work that he believed was open to all, geared toward “the lost travelers of the world.”

“I don’t think their appeal is to any particular class of people,” he told The Washington Post in 1973. “Just people who are open. One has to be empty to see. Most people, though, are deliberately full 24 hours a day, except sometimes in their dreams. These are films for when you want to be quiet a while, and feel pleased with the world.”