While law enforcement searched a nearby mountainside last week, Redwine was in Indianapolis, handing out fliers to truck drivers so they could look for his child on their routes.
"I was on a mission to take Dylan's story nationally," Redwine tells PEOPLE. "I always held out hope that I would see my son again."
Instead, he received a call no parent wants to hear.
"They needed me to identify some items of interest," Redwine says. He drove 1,400 miles back to Colorado in fewer than 30 hours and met with deputies, who handed him a binder full of photos. While searching in Vallecito Lake, Colo., not even 10 miles from Redwine's home, police had discovered five human bones, which they later confirmed were Dylan's.
"Where's the remaining 98 percent of my son?" Redwine asks, his voice cracking. Police told him wild animals likely ravaged the rest.
War of WordsPolice say Dylan's disappearance is an ongoing criminal investigation. But Mark Redwine's ex-wife Elaine, for one, wonders if her former husband had something to do with it.
They appeared on the Dr. Phil show in February and got into a heated exchange, pointing fingers and shouting accusations. "I didn't lose Dylan," Mark said. "Then why is he gone?" Elaine asked. "You have to answer that question. You had him. Where is he?"
Attempts to reach Elaine for this story were unsuccessful. But the couple's eldest son, Cory, 21, also questions his father's role. "Mark is holding the key," Cory told CBS4 in Denver. "We strongly believe that the last person to see Dylan knows the truth."
Mark Redwine says he came home from doing errands last Nov. 19 to find that Dylan – who was visiting for the week – was gone. "The TV was on. There was a bowl and box of cereal out," he recalls. "After a couple of hours, I got concerned."
Police have not named any suspects. Redwine flatly denies being involved in his son's disappearance. "Absolutely not," he says.
He continues to assist investigators and hopes to eventually give his son a proper burial. But, for now, he has no answers. "We may never know the truth," he says.
Meanwhile, Elaine is trying to cope with how her son died.
"The fact that his bones were spread, the fact that wildlife got to him – whoever did this is just a monster," she tells Denver's KUSA-TV. "He deserved so much more than to just have his remains eaten by wildlife."