When Sean "Stanley" Leary's friends heard he'd gone missing in Utah's Zion National Park, they drove hundreds of miles to help.

Leary was well-known in the tight-knit world of mountain adventurers. At Yosemite National Park, he was an old hand, with more than 50 ascents of El Capitan under his belt — including a record-setting 2 1/2-hour scramble up a 2,900-foot wall that demands several days from seasoned climbers. He explored new routes up peaks in the Arctic and in Antarctica and was an ardent BASE jumper — an adventure enthusiast who leaps off mountains and other high places.

In 2009, he leaped from a peak in Patagonia called El Mocho to spread the ashes of his girlfriend, a climber who was killed in a car crash, over the mountains she loved.

PHOTOS: Sean "Stanley" Leary on a climbing expedition to Antartica

He had jumped in remote spots throughout the world and he was familiar with Zion's desert stillness and haunting rock formations.

He was due back in California on March 23. When he didn't return, worried relatives alerted park officials.

Hours later, Leary's body, rigged up in his BASE jumping gear, was found 300 feet beneath a high ridge in the park's West Temple area. Because of weather delays, his remains were not recovered until Tuesday.

He was 38 and about to become a father.

BASE stands for buildings, antennae, spans (such as bridges) and earth (meaning cliffs and mountaintops). BASE jumpers often use wingsuits that help them glide before releasing parachutes that slow their descent.

Leary took up BASE jumping after the 2006 death of world-class Brazilian climber Roberta Nunes in a rollover accident on a Utah highway. She was driving and died in his arms. Devastated, he found solace in a typically high-energy fashion.

"I needed something new that would take me to a different spot," he once told an interviewer. "After Roberta died, I took up BASE jumping because it felt like a release."

Those who knew him say it worked.

"It helped him survive," said his sister, Erin Martin. "When he was flying, it was the happiest point of his life."

BASE jumping is illegal in national parks. Authorities at Zion said Leary's solo jump was well within the park's boundaries. Other climbers and jumpers said Leary was dedicated to finding "exits" — the jumpers' term for takeoff points — on public lands where the sport is not forbidden.

In either case, Leary's moments aloft buoyed his spirit.

He once described the adrenaline-pumping thrill as "watching the previously inconceivable turn into the possible."

"There's a second of absolute freedom," he told filmmaker Chad Copeland. "You're floating, you're floating — it's just magic when the wingsuit pops open and inflates and you start to take off."

In 2009, on an expedition captured in the television series "First Ascent," Leary packed Nunes' ashes into his parachute and, soaring off a remote peak, released them in a cathartic puff of white.

It was a promise he had made to her just days before her death, and it took him more than 2 1/2 years to fulfill it.

Friends said the intensity of Leary's mourning enabled him to help others with their own.