Dylan Redwine, 13, disappeared Monday, the day after he arrived at the Vallecito home of his father Mark Redwine under a court-ordered visit for the Thanksgiving holiday.
About 200 volunteers and law enforcement personnel combed the area Saturday, including the Bayfield area he was known to frequent before moving to Colorado Springs last summer with his brother, mother and her boyfriend.
"There is nothing new at all, which is what makes it frustrating," La Plata County sheriff's spokesman Dan Bender told The Denver Post.
The boy is described as 5 feet tall and 105 pounds with blond hair and blue eyes. He was last seen wearing a blue-and-white Duke Blue Devils baseball cap, a black Nike T-shirt, black basketball shorts and black Nike Jordan shoes. He may have a black backpack.
Mark Redwine reported his son missing about 6 p.m. Monday after returning home from running errands.
The Post said a neighbor reportedly saw Dylan walking with another boy along a road in Vallecito Monday afternoon.