MORENCI (WKZO) -- It’s been two years since Andrew, Alexander and Tanner Skelton joined their father for a Thanksgiving weekend and vanished.

Their dad, John Skelton claims he gave them away to a mysterious organization that handles secret adoptions but police believe he murdered them. He is serving 15-years for unlawful imprisonment.

Their family and friends marked the anniversary by unveiling a memorial to the boys this weekend, a large rock with a plaque and three trees planted at Wakefield Park in Morenci.

60-thousand dollars in reward money is available for information that leads to the location of the boys. Police have already received and checked out 13-hundred tips.