State and federal authorities were surveying damage in flood-ravaged southwestern Utah Wednesday that was expected to exceed $3 million.

Washington County Sheriff Kirk Smith said Wednesday morning that about 20 homes, many of them valued at between $500,000 and $1 million, have been literally washed away by floodwaters. Schools were canceled in the county Wednesday, and some regions were without telephone or 911 service on Tuesday.

Smith said floods were rare in the area, and few homeowners had flood insurance.

"The dams have done a great job for a while. We would've been fine this year, but we had tremendous amount of rain in October," he said.

The fall rains, combined with heavy snowmelt and additional rain over the past few days, has overflowed rivers and reservoirs throughout the region.

Television cameras have captured images of houses crumbling into surging floodwaters.

After touring the damage, Gov. Jon Huntsman (search) declared Washington County a state disaster area — a key step toward acquiring federal aid.

"It's a situation that one must see to believe. It's truly a disaster area in some respects. Property has been lost, homes have been lost, families have been relocated," Huntsman said. "Small towns like Gunlock, with 350 people, have been completely isolated and cut off from the outside world."

National Guard helicopters airlifted people out of the Gunlock and Motoqua areas, said Chief Perry Lambert, a spokesman for the Washington County emergency operations center. The areas, northwest of St. George, were left stranded when a bridge was knocked out by the wide and powerful storms.

The Utah National Guard (search) was also delivering supplies to those areas for remaining residents, he said.

State and county officials throughout the region also were working to arrange medical care, water, food and shelter for the displaced, Huntsman said.

Residents in nearby Green Valley were also without phone service, including 911 service, for more than an hour Tuesday night.

Smith said the water level had dropped 4 feet to 6 feet by Wednesday morning, signaling hope for the flood-ravaged communities that they could finally begin rebuilding after the damage.

"Basically we're trying to gear up for the recovery phase," Lambert said. "Not a sandbagging thing as much as rebuilding roads and infrastructure."

The Virgin, Santa Clara and San Juan rivers were all likely to continue running high in southern Utah before receding Wednesday. Rain in the area was likely to change to snow sometime Wednesday, National Weather Service (search) hydrologist Brian McInerey said.

The storm also continued to dump heavy snow on Utah's mountain ranges and shut down the Alta ski resort Tuesday.

The flooding around St. George is the worst in McInerey's 15 years at the NWS, he said.

"The soils are totally saturated in the area, so any rainfall that falls will be transformed into a river," McInerey said. "Think of it as a wet sponge and everything is just running off it."

Flooding started in the St. George area Monday morning, damaging roads, filling city sewer systems with dirty river water and flooding several residences.

Access to the tiny community of Gunlock was cut off when a bridge was pushed from its footings by flood waters, St. George police spokesman Craig Harding said.

"Gunlock is basically isolated, because the only ways in and out are cut off," said Derek Jensen, spokesman for the state's Department of Public Safety.

Five bridges in the area — one each north and south of Gunlock, the Shim bridge, and bridges in Toquerville and New Harmony — had buckled or were on unstable footings and had been ruled impassable. The well-used Shivwits bridge in Washington County also was out after it buckled under the weight of the rushing water.

At least one death has been linked to the floods. A man driving near Quail Creek Reservoir climbed onto the roof of his SUV Monday after getting trapped in a flooded wash. The man was swept away, and his body hasn't been found. No other injuries have been reported.

Washington County remained under a state of emergency, and officials were sending assistance, including about 50,000 sandbags.

Northern Utah did not escape trouble, and Lt. Gov. Gary Herbert planned to assess damage in Cache, Rich and Box Elder counties on Wednesday. More than a dozen homes in Pleasant Grove in Utah County were flooded Monday when storm drains spilled over.

In Logan, where nearly 20 inches of snow had accumulated since Saturday, some residents had spotty electrical service after wet, heavy snow took out tree branches and downed some power lines. A Smith's grocery store was evacuated after its roof bowed under the weight of heavy snow.

Alta ski area, which shut down Tuesday because of avalanche danger, said it had received snow every day since Dec. 27, totaling more than nine feet.