Rescue teams are warning people in some Colorado towns isolated by devastating flooding against remaining there, telling them they could face weeks without basic supplies, including running water and electricity.
Helicopters and truck convoys of the National Guard carried the admonition Saturday into paralyzed canyon communities where thousands of stranded residents were eager to escape the Rocky Mountain foothills. But not everybody was willing to go. Dozens of people in hard hit Jamestown wanted to stay to watch over their homes.
Colorado Gov. John Hickenlooper saw some of the damage from the air Saturday. His tour quickly turned into a rescue mission in which the crew pulled seven people into the chopper.
The National Guard said the rescue is one of its biggest such missions in years.
"I think what we have going on here in the last 24 hours is the greatest number of Americans rescued by helicopter since Hurricane Katrina," said Lt. Col. Mitch Utterback of the National Guard.
Four people have been confirmed dead since the harrowing floods began Wednesday. And hundreds of others have not been heard from in the flood zone, which has grown to cover portions of an area nearly the size of Connecticut.
Some of those who are unaccounted for may be stranded or injured. Others might have gotten out but not yet contacted friends and relatives, officials said.
Authorities made clear that residents who chose not to leave might not get another chance for a while. Rescuers won't go back for people who insist on staying, Boulder County Sheriff Joe Pelle said.
"We're not trying to force anyone from their home. We're not trying to be forceful, but we're trying to be very factual and definitive about the consequences of their decision, and we hope that they will come down," Pelle said.
Across the foothills, rescuers made progress against the floodwaters. But they were still unable to go up many narrow canyon roads that were either underwater or washed out.
Meanwhile, President Barack Obama signed a disaster declaration and ordered federal aid for Colorado. The White House said in a statement Saturday night that the action makes federal funding available to affected individuals in Boulder County. The government said that other counties could be added later.
The city of Longmont ordered a curfew from 10 p.m. Saturday until 6 a.m. Sunday in flood zones and evacuation areas, urging residents to remain indoors.
On Saturday, the surge of water reached the plains east of the mountains, cutting off more communities and diverting some rescue operations.
Police expected to find more bodies as the full scope of damage emerges.
A woman was missing and presumed dead after witnesses saw floodwaters from the Big Thompson River destroy her home in the Cedar Cove area, Larimer County sheriff's spokesman John Schulz said.
"I expect that we're going to continue to receive reports of confirmed missing and confirmed fatalities throughout the next several days," he said.
Two fatalities were identified by the Boulder County coroner Saturday as Wesley Quinlan and Wiyanna Nelson, both 19.
Authorities believe the couple died when they were swept away after driving into floodwaters and then leaving their vehicle. Their cause of death is under investigation.
The military put more troops on the ground and helicopters in the air to aid in the search-and-rescue effort. By Saturday night, 1,750 people and 300 pets had been evacuated from Boulder and Larimer County, National Guard Lt. James Goff said.
The airlifts are continuing Sunday with helicopter crews expanding their searches east to include Longmont, Fort Collins and Weld County.
More than 85 fifth-graders from Louisville were greeted by their parents and friends Saturday after they were rescued from an outdoor education center near Jamestown.
Above Larimer County, rescue crews airlifted 475 people to safety and planned to resume helicopter searches on Sunday, weather permitting.
Rain was expected to start up again in the mountains and foothills, with between a half-inch and 2 inches forecast to fall overnight, according to the National Weather Service.
Crews also used inflatable boats to pick up families and pets from farmhouses on Saturday. Some evacuees on horseback had to be escorted to safe ground.
Near Greeley, 35 miles east of the foothills, broad swaths of farmland had become lakes, and the raging South Platte and Poudre rivers surrounded more homes.
In one Boulder neighborhood, residents turned back city crews and machinery that arrived to remove the makeshift berms and sand-filled trash bags protecting their homes. University of Colorado students helped homeowners improvise a way to divert the rising water from Gregory Creek.
"The residents know better than anybody else how the water flows through the neighborhood," said Colleen Scanlan Lyons.
In communities where floodwaters began receding, homeowners had a chance to assess damage.
In Laporte, Wendy Clark surveyed soggy carpets and furniture that got damaged by the Poudre River.
"This mud smells disgusting," she said. "I don't know how long that's going to be around."
Information from the Associated Press was included in this report.