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 will continue Sunday with helicopter crews expanding their searches east to include Longmont, Fort Collins and Weld County.
It was not clear how many people were still stranded.
A helicopter taking Gov. John Hickenlooper on a tour of the flooded areas even got in the act, stopping twice to pick up six stranded people and their two pets. Terry Kishiyama’s son flagged down a helicopter with his shirt after a three-day wait for rescue from a neighbor’s house on higher ground.
“You could hear the choppers for miles and miles, but I didn’t know if they were evacuating people. You see a chopper going down behind a ridge, and you have no clue,” Kishiyama said.
In addition to his son’s efforts, Kishiyama said his wife shouted at the chopper, “We have babies!”
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.