A search team found the body of Colorado Sen. Mark Udall's brother in western Wyoming's Wind River Range on Wednesday after he didn't return from a solo backpacking trip, the family said.
James "Randy" Udall, 61, had left June 20 for the weeklong trek, setting off from a trailhead 10 miles northwest of Pinedale. He was due back a week ago.
An aerial team spotted Udall's body on its side, in open, rolling terrain Wednesday afternoon, Sublette County sheriff's officials said. The body was taken to Pinedale.
Mark Udall's office released a statement from the family saying that while an autopsy is forthcoming, it appears his brother died of natural causes.
"Randy left this earth doing what he loved most: hiking in his most favorite mountain range in the world," the family said.
He had told his wife and indicated on a sign-in sheet at the trailhead that he planned to head for the scenic Titcomb Basin.
The family said Wednesday it appeared he was on the obscure, off-trail route that he had proposed to his family.
"The entire Udall family is touched beyond words by the tremendous outpouring of support from people around the country. Randy's passing is a reminder to all of us to live every day to its fullest, just as he did," they said.
Randy Udall was an environmentalist and energy efficiency advocate whose family has been active in politics.
New Mexico Sen. Tom Udall is a cousin. His uncle, Stewart Udall, was interior secretary in the 1960s. His father was the late U.S. Rep. Morris "Mo" Udall of Arizona.
"He was an extraordinary person who touched so many lives," Tom Udall said. "Randy and I were especially close. We shared a love of the mountains and a passion for the wonders of the West, particularly the Wind River Mountains where we hiked and fished together nearly every summer for three decades."
Randy Udall helped found the nonprofit Community Office for Resource Energy Efficiency, which promotes the use of renewable energy in the Aspen, Colo., area.