DENVER — Seven people were confirmed dead, and at least 1,500 homes destroyed in Colorado after a week of rare, torrential rains along the eastern slopes of the Rockies. Helicopter search-and-rescue flights resumed this week in flood-stricken areas.

Much of the evacuation effort was focused on remote foothill and canyon communities of Larimer and Boulder counties in north-central Colorado, where 1,000 residents remained stranded due to washed-out roads, bridges and communication lines, the county sheriff’s office said.

Ranchers were advised to move livestock away from rain-swollen streams as floodwaters spread further east onto the prairie, and authorities warned residents to be on the lookout for rattlesnakes that might be moving to higher ground.

Flash floods first unleashed last week by heavy rains that started Monday, Sept. 9, and drenched Colorado’s biggest urban centers along a 130-mile stretch in the Front Range of the Rockies.

At the peak of the disaster, the heaviest deluge to hit the region in four decades, floodwaters streamed down rain-saturated mountainsides northwest of Denver and spilled through canyons, funneling the runoff into populated areas below.

President Barack Obama declared the area a major disaster over the weekend, freeing up federal funds and resources to aid state and local governments.