More than a week later, police are searching Colorado reservoirs and neighborhoods but still don't know what happened to the boy.
Dylan's father picked him up on Nov. 18 at Durango-La Plata County Airport. The boy announced his arrival in Vallecito in a text message that ended with a scowling emoticon, said Elaine Redwine, his mother.
The next day, while his father ran an errand, he disappeared after setting off to meet friends in the secluded vacation spot high in the mountains near Durango.
Authorities don't believe Dylan ran away. They say he has a cellphone and has not contacted any of his friends in nearby Bayfield, where he previously went to school.
On Thursday, authorities served a search warrant at the father's home.
According to the Durango Herald, Colorado Bureau of Investigation and the FBI also set up tents and a trailer outside the house. Investigators wearing white scrub-like uniforms made trips in and out of the house and a travel trailer on Thursday.
La Plata County sheriff's spokesman Dan Bender said authorities are focusing on the possibility of foul play but hope that isn't the case.
At this point, they consider their effort to be a search, not a recovery mission, he said. Bender said it was only prudent to search the house and not an indication any suspects have been identified.
"We've been doing a potential criminal investigation, looking at abduction, kidnapping or foul play. We haven't closed out the possibility he has run away and we're still going door to door. We have an absence of clues. It's a mystery, that's what makes it so frustrating," he said.
Bender did not return a phone call from The Associated Press seeking details on the search warrant.
Elaine Redwine told ABC News that she fears Dylan's father, Mark Redwine, might have had a problem with the boy.
"If Dylan maybe did or said something that wasn't what Mark wanted to hear, I'm just afraid of how Mark would have reacted," she said.
Mark Redwine said he didn't want to respond to the fears of his ex-wife.
"I don't want to lash out," he told the Durango Herald.
Police have declined to comment on the suggestion.
The parents did not respond to requests for comment from the AP.
Bender said the parents divorced in 2007, and a court ordered Dylan to live with his mother while granting visitation rights for the father.
Bender refused to comment on the divorce or the suggestion by Elaine Redwine, but said, "If you're the parent of a child and haven't heard from him in several days, that would be difficult for anyone."
Lia Howard, the sister of Elaine Redwine, said the family has told authorities Dylan didn't run away. She also said Dylan wanted to spend Thanksgiving with family members in Castle Rock and was disappointed he had to go to see his father.
Elaine's boyfriend, Mike Hall, who lives with the mother in Colorado Springs, declined to speculate on what might have happened to Dylan.
"I just hope we can get him back," Hall said. "We're very grateful for the support of everyone that's trying to help in that community."
Authorities, including the FBI and Colorado State Police, are using satellites to map neighborhoods and asking the public for any video footage that includes vehicles traveling on main routes between Durango and Vallecito Lake around the time Dylan went missing.
Little has been revealed about the results of the search. A few days ago, there was a spark of hope after part of a fishing pole was found on a dam, prompting a two-day search of the area that turned up empty.
Investigators determined the discovery had no connection to the case after they located the owner of the broken pole.
The missing boy is 5 feet tall, weighs 105 pounds and has blond hair, blue eyes and fair complexion. He was last seen wearing a blue-and-white Duke Blue Devils baseball cap, black Nike T-shirt and black Jordan tennis shoes.