In their analysis, the Colorado researchers said the preliminary evidence was circumstantial; the bones confirmed that the body was male, Caucasian, 19 to 22 years old, and about 5 feet 8 inches tall  all a match for Mr. Ruess. The jaw and eye sockets were largely intact, and so a facial reconstruction came next. It closely matched photographs of Mr. Ruess taken by Ms. Lange, a photographer probably best known for her images of migrant workers during the Depression.

Finally, DNA extracted from the bones showed a 25 percent match with nephews and nieces of Mr. Ruess, the exact amount that would be expected in that family relationship. The conclusion, said Kenneth Krauter, a professor of molecular, cellular and developmental biology at Colorado, was “irrefutable.”

How the remains were found at all is an astonishing tale in its own right.

That story begins in the early 1970s, when Aneth Nez broke a 37-year silence to tell his family about being witness to a dark incident in the 1930s. He told them that while sitting on a ridge, he watched three Ute boys chase down and kill a young white man. After the killers took the victim’s two mules, Mr. Nez, out of respect, buried the body, he told his granddaughter, Daisy Johnson, but was too afraid to talk about it.

Image A photograph of Everett Ruess by Dorothea Lange, with photographic superimposition of skeletal remains found in southern Utah done by Paul Sandberg of the University of Colorado at Boulder. Credit... Courtesy of National Geographic Adventure Magazine

Last year, Ms. Johnson told the story to her younger brother, Denny Bellson, and together, on May 25, they went to the general area their grandfather had talked about. Mr. Bellson, speaking in the conference call, said he saw a saddle first probably his grandfather’s, which, in the Navajo tradition, he would have disposed of because it had been contaminated by coming in contact with the blood of the dead. Then, Mr. Bellson said, he saw the bones, jammed down into a rock crevice.

“The skull was in pieces,” he said. But he said he also saw that it was indented, as though caved in, which fit with his grandfather’s tale.

One of Mr. Ruess’s nephews, Brian Ruess, said in a telephone interview that he had grown up with open-ended versions of his uncle’s story, with each family member drawn to speculate. Some wanted to think their uncle had fallen in love with a Navajo girl and intentionally disappeared into the desert. Brian Ruess said he had always imagined his uncle being swept away while crossing the Colorado River.