Rain and melting snow swamped Nevada on Saturday, causing the worst flooding in the Reno area since a January 1997 flood that caused $1 billion in damages.

High water and mudslides closed major roads, including Interstate 80 about 25 miles west of Reno and Highway 89 near Truckee, Calif.

I-80 — the major corridor linking northern California and points east — was expected to remain closed for at least two days, said California Department of Transportation spokesman Mark Dinger.

Six truck rigs were caught in the mudslide early Saturday, but no injuries were reported. It will cost about $5 million to clean up the slide, officials said.

"No work can be done until the slide stabilizes and we don't know when that will occur," Dinger said. "Certainly, I-80 could be closed for longer than two days."

Up to 1-2 inches of rain on valley floors and 6-8 inches of rain in the Lake Tahoe area prompted flood warnings along the eastern Sierra.

Flood waters inundated an undetermined number businesses Saturday morning along the Truckee River in east Reno and Sparks, said Regional Emergency Operations Center spokesman Steve Frady.

The Truckee was expected to crest early Saturday afternoon in downtown Reno at 13 feet, 2 feet above flood stage. Just to the east in Sparks, it was expected to crest at 22 feet, 7 feet above flood stage.

While those levels are near those of the 1997 New Year's Day flood, officials stress water flows will be substantially less because upstream reservoirs are well below capacity.

"We're hoping the snow level falls and the situation doesn't turn out as bad as projected," Frady said. "But there are businesses sandbagging right now to prepare for the worst."

While Reno casinos remained open Saturday morning, all three Truckee River bridges in the downtown were closed.

Water was flowing over at least one of them, and crews were working to prevent trees and other debris from blocking the river's flow under the bridges.

Crews also were trying to prevent the Reno Hilton's huge outdoor pond from overflowing onto nearby Reno-Tahoe International Airport. The 1997 flood shut down the airport.

"That's been a top priority," Frady said. "It's really critical to keep the airport open, especially if we end up with a two-day closure of I-80."

Two Sparks trailer parks along the Truckee and two such Dayton parks along the Carson River were evacuated Saturday morning.

Flood waters reduced U.S. 395 to one travel lane in each direction south of Reno.