“Folks who haven’t had direct experience of open-air cremation, whether it’s in Colorado or in Asia, can have some pretty strange associations,” said Angela Lutzenberger, a hospice chaplain who bought 63 acres of land in Dresden, Maine, that she hopes to turn into a pyre site. “They build up creepy ideas about what it could be.”

It is not a coincidence that Crestone is the pyre’s home. About 200 miles south of Denver, the former gold mining town has attracted a population drawn to Eastern religious practices and wisdom traditions for decades. Its reputation solidified in the 1980s, when a Danish-born spiritual seeker and her oil magnate husband established a sprawling development just outside town that bills itself as the “largest intentional, interreligious and sustainable living community in North America.”

The winding roads around that development — with street names like Serene Way and Jubilant Way — lead to several towering Buddhist shrines, retreat centers and a spiral ziggurat commissioned in the 1970s by the father of Jordan’s Queen Noor. Some locals refer to a “vortex” of energy in the area.

“There’s no other place quite like this in America,” said Dr. Incao’s son Sylvan, who visited his father there often over the years.

Sylvan had come to Crestone on a chilly week in March that would culminate in his father’s cremation. Fliers with information about the ceremony were posted at the health food store and the cafe next door, which function as the town’s social center. “Please carpool whenever possible,” the flier read. “Pyre lit at 8 AM.”

Dr. Incao had moved to Crestone with his second wife, Jennifer, in 2006, after practicing “anthroposophic” medicine — a Steiner-inspired holistic approach that many mainstream physicians characterize as pseudoscience — in upstate New York and Denver.

Dr. Incao graduated from the Albert Einstein College of Medicine in New York City, but his career radically changed course when he was introduced to alternative medicine and Steiner’s work. Steiner lectured widely on topics including philosophy, Christianity, finance, architecture and art. His ideas about education led to the Waldorf school movement; his thinking on agriculture inspired biodynamic farming.

Steiner’s view of medicine was a revelation for Dr. Incao. He went on to spend his life exploring the teachings of Steiner, whose work guided not just his interest in philosophy and spirituality but his medical career.

He believed in reincarnation, which he felt gave a sense of purpose to life. And he was devoted to the idea of what he considered a “natural” approach to medicine.

For Dr. Incao, that meant choices that would seem extreme to many, even some members of his family. He strongly opposed vaccination, publishing articles and offering testimony against childhood vaccines and eventually opposing the Covid-19 shots. When he became sick, he declined traditional treatments for his cancer, including chemotherapy. He was at home in Crestone, where many residents are skeptical of traditional medicine.

Dr. Incao believed that the moment of death was just the beginning of “the process of separation of the human identity,” which he said took about three days.

And why be cremated outdoors? “You do it because it makes a lot more sense than the alternative, which is giving the body over to the undertaker,” he said. He decided on cremation after moving to Crestone, and officially signed up about four years ago.

Sylvan, 49, and his brother Sebastian, 47, supported their father’s plans, which they saw as in keeping with his spiritual sensibility and nonconformist streak. “He loved nature,” said Sebastian, an acupuncturist in New York. “It seemed like a very powerful way to liberate his spirit.”

Their older brother, Quentin, 51, was not so sure. He knew his father was a nonconformist, but he was still shocked when Dr. Incao told him about his intentions, on one of Quentin’s visits from his home in Montana. “It just didn’t make sense to me, I couldn’t understand it,” he recalled. He had agreed to be a pallbearer, but he was dreading the action of physically placing his father’s body on the pyre.

At a memorial service a few days before the cremation, the three brothers, their families and others gathered in Jennifer’s backyard art studio for a ceremony and eulogy delivered by a priest from the Christian Community, a small religious movement inspired by Steiner.

Dr. Incao’s body lay in repose at the front of the room, with wreaths of fresh carnations and other flowers on his body. “Into the calm of soul being walks the soul of our dear Philip,” the priest said, reading from a hand-transcribed book of sacred texts. “He is now on the other side of the threshold but his love has not stopped.” At the small outdoor reception afterward, deer grazed in the yard.

“It’s one of the most beautiful volunteer activities,” said Fane Burman, who has assisted at about a dozen cremations, helping stack the wood and tending to it as it burns. The nonprofit that operates the pyre, the Crestone End of Life Project, provides about a dozen local volunteers for each cremation. Although Mr. Burman does not always know the person who has died, “once the fire gets burning it brings tears to my eyes.”

On a cool Saturday, the family gathered at 7 a.m. to accompany Dr. Incao’s body from his home to the pyre about four miles west. A volunteer had wrapped the body in a shroud of sheets the night before and covered it in roses. The stretcher was carefully loaded into the back of Sylvan’s black pickup truck, and Quentin and Sebastian rode in the back with their father — “our last moments with him,” Quentin said. The truck slowly turned right at a small hand-painted sign reading “Pyre.”

By 7:30 a.m., about 70 people lined the path into the pyre site. A volunteer rang a bell to signify the start of the ceremony, and another played a tune on his handmade flute as the procession wound its way to the inside of the fence. The pallbearers laid the stretcher on the metal grate.

Dr. Incao’s ceremony began with family members and friends laying juniper branches and flowers on the body. Incense burned in a terra cotta pot tended by a volunteer, while others added logs until they were piled above the rim of the pyre. Then Jennifer and Dr. Incao’s sons lit large sticks in the incense pot and ignited the pyre together.

As the fire started to burn, Sylvan put his arm around Sebastian. A harpist played a tune as the flames crackled. Quentin wiped tears from his eyes, from smoke or emotion or both.

Smoke billowed thickly for about 10 minutes, and died down. By then, fire was putting off enough heat to warm the circle. Flaky ashes swirled in the air, which smelled of incense.

A “threshold choir,” which specializes in singing for the dying, performed some of the tunes they had sung for Dr. Incao in his last few months. “Safe passage, pilgrim of the spirit,” they sang. “We are all just walking each other home.”

Sylvan spoke about how he had always teased his father about wearing so many layers, always being cold. “With the fire going, he’s warm enough,” he concluded with a smile. Another friend performed a “hallelujah” — another Steiner concept — in which she solemnly circled the pyre, lifting and lowering her arms, moving forward and backward.

Quentin, who had questioned his father’s plans from the start, watched the ceremony quietly and intently. “It was almost like a weight lifted, to know he’s moved on,” he said later, as the crowd dispersed and the ashes smoldered.

He knew, in the end, it was what his father had wanted.

“He was looking forward to being the smoke.”