(Updates with latest property loss estimates, casualty counts)
By Keith Coffman
DENVER, Sept 16 (Reuters) - Seven people were confirmed dead from flooding triggered by a week of torrential downpours along the eastern slopes of the Rockies in Colorado, the Boulder County Office of Emergency Management said on Monday.
County office spokeswoman Liz Donaghey said the latest tally came from the Federal Emergency Management Agency, but a breakdown of the seven deaths was not immediately available.
Separately, two women, aged 60 and 80, remained missing and presumed dead after their homes were washed away by flash flooding in the Big Thompson Canyon area, Larimer County sheriff's spokeswoman Jennifer Hillman said.
Authorities in Larimer County, in north-central Colorado, were still not counting those two women as confirmed fatalities because their bodies had yet to be recovered, Hillman said.
Nearly 400 other people remain unaccounted for in Larimer County, with many believed to be still stranded in remote areas cut off by floodwaters and left without telephone, cell phone or Internet service, she said.
Larimer County was among the areas hardest hit by floods first unleashed last Wednesday night by sustained heavy rains that have drenched Colorado's biggest urban centers along a 130-mile (210 km) stretch in the Front Range of the Rockies.
An estimated 1,500 homes have been destroyed and 4,500 more damaged in Larimer County alone, Hillman said. In addition, 200 businesses have been lost and 500 damaged, she said, citing preliminary assessments by the county.
Foothill communities in the adjacent counties of Larimer and Boulder, northwest of Denver, bore the brunt of the disaster as floodwaters streamed down rain-soaked mountainsides and spilled through canyons funneling the runoff into populated areas below.
MASSIVE RESCUE OPERATION
The flooding progressed downstream and spread onto the prairie over the weekend, much of it spilling over the banks of the South Platte River and inundating farmland as high water rolled eastward in the direction of Nebraska.
Overall, the flood zone encompassed an area nearly the size of Delaware.
As the weather began to clear Sunday night and Monday, rescue workers fanned out across flood-hit portions of Colorado.
"They'll take advantage of the weather today and help out everyone they can," said Micki Trost, a spokeswoman for the state Office of Emergency Management. "We hope that those weather forecasts stay in our favor."
A light drizzle and patchy fog continued to hamper helicopter rescue missions early on Monday, according to Byron Louis of the National Weather Service office in Boulder.
The air rescue operations were the largest in the United States since flooding in the aftermath of Hurricane Katrina devastated New Orleans in 2005, National Guard officials said.
Louis said some areas had been soaked by as much as 16 inches (40 cm) of rain in just three days, the average for an entire year.
President Barack Obama declared the area a major disaster over the weekend, freeing up federal funds and resources to aid state and local governments.
U.S. Army and National Guard troops have rescued 1,750 people cut off by washed-out roads in the mountain canyons of Boulder and Larimer counties, Army spokesman Major Earl Brown said in a statement.
State officials would be unable to assess the overall damage until rescue efforts were complete and the floodwaters receded, Trost said. (Reporting by Keith Coffman; Writing by Steve Gorman; Additional reporting by Tom Brown; Editing by Dan Whitcomb and Richard Chang)