"We're sure there are going to be additional homes that have been destroyed, but we won't know that for a while," Schulz said. "I expect that we're going to continue to receive reports of confirmed missing and confirmed fatalities throughout the next several days."
Four people have been confirmed dead since the harrowing floods began Wednesday. More than 170 people remained unaccounted for in Boulder County, but that number could include people who are still stranded or who escaped but have not made contact yet, said Boulder County Sheriff Joe Pelle.
National Guard helicopters flew in and out of the mountain hamlet of Jamestown late into Friday night after it became isolated by rushing water that scoured the canyon the village sits in. Rescuers on the ground focused on the town of Lyons, a gateway community to Rocky Mountain National Park.
By Saturday morning, the Guard had evacuated nearly 800 people by air and ground.
More than a dozen helicopters were available to aid with rescue efforts.
"We have the ability to go whenever, wherever," Master Sgt. Cheresa Theiral said.
Still more rain was expected Saturday. And the outlook for anyone who preferred to stay behind was bleak: weeks without power, cellphone service or running water.
"Essentially, what they were threatening us with is, 'If you stay here, you may be here for a month,'" said 79-year-old Dean Hollenbaugh, who was evacuated by helicopter from Jamestown, northwest of Boulder.