Colorado Senator Mark Udall's younger brother James is missing in Wyoming, several days after the experienced hiker was due to return from a week-long solo excursion in the Wind River Range mountains. 

James "Randy" Udall, 61, is an experienced hiker and would have been familiar with the area, according to the Subette County Sheriff's Office. On Friday, he was reported missing. That's two days after he was scheduled to return. Crews have been searching for him since Friday afternoon. According to the Denver Post, the search effort includes ground and ariel teams, covering a nearly 225 square mile area, with assistance from the U.S. Forestry service.

Speaking to the Denver Post, Udall's office said the senator has known since last week. Here's what his office told the paper: 

"In that time, (Sen. Udall) has remained in contact with those searching for his brother and, along with his family, has waited and hoped for the best," spokesman James Owens said. "Nonetheless, he knows he still has a duty to lead — even with his brother missing — and has continued to serve while closely following the search."
 

James is also the first cousin of New Mexico Senator Tom Udall, also a Democrat. 

Photo: Handout, Subette County Sheriff's Office.