Esau Antonio Castaneda Vargas was 20 when he vanished in the Arizona desert in the summer of 2009. He was last seen June 15, 2009, near Lukeville in Pima County. Reports describe him as Hispanic, black hair, brown eyes, between 5 feet 4 inches and 5 feet 6 inches tall, and 160 to 175 pounds, with a large scar on his knee, a scar on his foot, and a mole on his lower leg.

At the time he disappeared he was wearing gray Dickies pants, a blue, black and white striped shirt, a black or white baseball cap with LA on the front, and white Adidas shoes with black stripes. He also wore a red bracelet and a homemade rope belt, may have been carrying a prayer card for Malverde, and may have been using the alias Agustin Sanchez Nava.

Friends who were crossing the border with him told his girlfriend that Esau became exhausted and overheated and was left at a location called cerro de las chichis, described as about five hours from an intersection of Interstate 8 and a road toward Maricopa, possibly near Gila Bend. The date he was left is uncertain and might have been as late as June 24. One companion reportedly tried to return for him and later died in the desert; what ultimately happened to Esau remains unknown.

If anyone knew Esau, his movements in June 2009, or the area described as cerro de las chichis, please share information with investigators.