Aubrey Sacco, 22, left Greeley, Colorado, for a self-styled trip through Asia late in 2009 and was last seen in Nepal in April 2010. Family members dropped her at Denver International Airport on December 13, 2009, and she traveled through India and Nepal while keeping regular contact with her parents. The last confirmed contact was an April 20, 2010, message that she had arrived in Nepal to begin a solo trek in Langtang National Park.

Villagers saw Aubrey on April 22, 2010, at the Lama Hotel and at the Sherpa Lodge, where witnesses say she argued with three local men about the distance to her next stop, consulted her map, and continued alone. She never reached her destination and did not return when expected. Some personal items were recovered at the last hotel. Arrests reported in 2013 were dropped after a confession was judged unreliable and no charges were filed. Her family has continued travel to Nepal and worked with local authorities, the FBI, and private investigators, but the case remains unresolved.