Authorities are going door-to-door looking for a 13-year-old boy missing for more than a week in southwestern Colorado.

La Plata County sheriff’s spokesman Dan Bender says investigators are no longer looking at the possibility that Dylan Redwine ran away while visiting his father at Vallecito for Thanksgiving break.

Bender also says investigators still view their operation as a search, not a recovery mission, but he didn’t elaborate on why.

The boy’s mother, Elaine Redwine, of Colorado Springs, told ABC News she thinks her ex-husband, Mark Redwine, may be involved in her son’s disappearance.

Mark Redwine says he wishes he and his ex-wife could come together at such a difficult time.

He reported Dylan missing after he left the boy at home Nov. 19 to run errands.