LYONS, Colo. — The cars that normally clog Main Street in Lyons on the way to Rocky Mountain National Park have been replaced by military supply trucks. Shop owners in Estes Park hurriedly cleared their wares in fear that the Big Thompson River will rise again. A plywood sign encouraged residents mucking out their homes to “Hang in there.”

Days of rain and floods have transformed the outdoorsy mountain communities in Colorado’s Rocky Mountain foothills affectionately known “The Gore-Tex Vortex” from a paradise into a disaster area with little in the way of supplies or services — and more rain falling Sunday.

The string of communities from Boulder to Estes Park, the gateway to Rocky Mountain National Park, is a base for backpackers and nature lovers where blue-collar and yuppie sensibilities exist side by side. Now, roadways have crumbled, scenic bridges are destroyed, the site of the bluegrass festival is washed out, and most shops are closed.

Chris Rodes, one of Lyons’ newest residents, said the change is so drastic that he is considering moving away just two weeks after settling there.

“It’s not the same,” Rodes said. “All these beautiful places, it’s just brown mud.”

Numerous pockets of individuals remained cut off by the flooding. Sunday’s rain hampered the helicopter searches, and rescuers trekked by ground up dangerous canyon roads to reach some of those homes isolated since Wednesday.

The surging waters have been deadly, with four people confirmed dead and two more missing and presumed dead after their homes were swept away.

Hundreds of people have still not been heard from, but with phone service being restored to some of the areas during the weekend, officials hoped that number would drop as they contacted more stranded people.

As rescuers broke through to flood-ravaged towns, they issued a stern warning Saturday to anyone thinking of staying behind: Leave now or be prepared to endure weeks without electricity, running water and basic supplies.

National Guard helicopters and truck convoys carried the admonition 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 the isolated community of Jamestown wanted to stay to watch over their homes.

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.

Special education teacher Brian Shultz, 38, was torn about leaving his Jamestown home.

“I was thinking about staying. I could have lasted at least a year. I have a lot of training in wilderness survival,” he said, adding that he probably had enough beer to last the whole time.

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.

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 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.