James "Jimmy" Hendricks set out across the American West, bearing the ashes of his late father, in a journey nearly five years in the making.

Hendricks, 66, inherited a love for nature from his father, which inspired what he called "Travels with Neil: A Final Journey with My Father."

He began the trip at the Caverns of Sonora in Texas and intended to stop at special places along the way to Mount Rose in Nevada. It was a place his father used to visit before his death in 2018, and it was there he planned to spread the ashes.

The trip was regularly documented on social media and through a group email with his sisters, who grew concerned after not hearing from him for several days.

"The last time I spoke to Jimmy was in a quick email on July 28th about some photos he had shared," Ruth Hendricks Brough told CNN.

A day later, Hendricks woke up at the Moab Red Stone Inn extra early for a day of hiking and photography at Arches National Park.

Security footage shows him staggering into his van looking dizzy and weak around 6:30 a.m., Brough said.

Hendricks first hiked the Sand Dune Arch Trail, which the National Park Service describes as an easy hike with a round-trip distance of 0.4 miles. From there, he went on to complete the Broken Arch Loop Trail, which is listed as a moderately difficult 2.3-mile hike.

Brough added, "If someone had been there with him, they would've noticed right away that he was not in any condition to go out in the heat."

All are of the dust, and all turn to dust again

Hendricks' body was found inside a Utah national park on Aug. 1 after being reported overdue, with an empty water bottle close to his side, according to a news release from the National Park Service.

"He was just not in the condition to try that, and then he wandered off that trail for some distance and died," Brough told CNN.

"He just didn't have enough water on him when he was hiking, and even if he had, he might not have been able to survive," Brough said. "He'd done extensive hiking and camping already at beautiful places between Austin, Texas, and Moab, Utah. So, he was more compromised than he realized."

Investigators have not released an official cause of death, which could take up to 12 weeks to determine, his sister Ila Hendricks told CNN. The Hendricks family plans to have a memorial once they are reunited with the ashes of their brother and father.

Ila Hendricks warned her brother of the heat wave before his trip, urging him to be safe.

"He said not to worry and that he would have plenty of water, but his water bottle was empty when he was found," she told CNN.

Hendricks was described as a magical spirit who exuded wonder and curiosity, despite hard circumstances.

"He cared for our mom from 1969 until her death in 2007 and our dad from 2010 until his death in 2018. He never got a chance for an education. Yet people assumed he was a university professor because he was a voracious reader all his life and endlessly curious about the world," Brough said.

The tragedy feels all too familiar to the Hendricks sisters, who lost their other brother Ron in a blizzard while visiting Marlette Lake, Nevada in 1992. His body was missing for more than 30 years. Reflecting on their deaths far from home, Brough made the connection.

"Both of them died of temperature extremes in a beautiful wilderness."