Jose Dejesus Pereda Alarcon, 69, of Arapahoe, Wyoming, was last seen driving south on South Federal Boulevard in Riverton, Wyoming, at approximately 11:30 a.m. on September 5, 2018. He was driving a white, single-cab 2002 Toyota pickup truck bearing Wyoming license plate 10-18870. Family members believed he was headed to the Sand Draw Landfill south of town, but he never arrived and has not been seen since. He was last seen wearing a gray and black long-sleeved flannel shirt and black pants. Pereda Alarcon, known by the nickname "Pepe," is diabetic and was reported to suffer from memory loss; authorities said at the time that he may have been confused or disoriented. His family reported him missing the same day, and the Fremont County Sheriff's Office was notified.
On September 19, 2018, an aerial search located Pereda Alarcon's truck stuck in a washout along Pipeline Road in a remote area of the Wind River Indian Reservation, roughly 10 miles east of Riverton near the Gas Hills area; he was not with the vehicle. A multi-day search involving ground crews, aircraft, ATVs, and a mounted patrol unit — coordinated by the Fremont County Sheriff's Office, Wind River Police Department, and tribal game and fish authorities — found no further trace of him, and the operation was later suspended. The Bureau of Indian Affairs' Wind River Agency subsequently took on the case as lead investigating agency, working alongside the Fremont County Sheriff's Office. Pereda Alarcon's family has offered a reward, increased over time to $10,500, for information leading to his location. As of 2026, he remains missing and the case remains open, still carried on the Wyoming Division of Criminal Investigation's missing-persons list. The case is catalogued with NamUs as MP52231. Anyone with information is asked to contact the Wind River Agency at 307-855-8292 or the Wyoming Division of Criminal Investigation at 307-777-7181. Case Number C18-05736.