Derrick James Tenorio, 21, disappeared late on the evening of August 5, 2011, in the Steamboat Standing Rock area of Steamboat, Arizona. A member of the Navajo Nation, he was last seen between 11:00 p.m. and midnight walking toward Steamboat Hill to visit his girlfriend but never arrived. Derrick was described as a Native American male with dark brown hair shaved short, brown eyes, standing between 5 feet 7 inches and 5 feet 9 inches, weighing 170 to 190 pounds, with a distinctive KAOS tattoo across the knuckles of one hand. He wore a red long-sleeved T-shirt, black Dickies-style pants, and tan steel-toed work boots that night.

His family — including two young children and a girlfriend who was pregnant at the time — reports troubling accounts from the night he vanished: an encounter with several people partying in the Standing Rock area, Derrick given vodka and painkillers, then running off into the woods after walking behind his brother. The family has long suspected foul play and mentioned concerns about increasing gang violence in the area while saying Derrick was not involved with gangs. The Navajo Nation Police Department, Window Rock District, is handling the investigation and the case remains unsolved.

Does anyone who was in the Steamboat Standing Rock area on the night of August 5, 2011, or who knew Derrick then, have information that could help the family?