An avalanche of rock and melting snow toppled into a mountain reservoir today, triggering a flood that killed at least one person, injured half a dozen others and destroyed or damaged five houses in the Davis Creek State Park area, 20 miles south of Reno.

The Washoe County coroner's office identified the victim as Joseph Valenzuela, a Gardnerville pastor.

Authorities were trying to locate the owners of several cars swept away by the flood.

County Sheriff Vince Swinney said the area was a popular place for hikers to park their cars before setting out to explore the Sierra Nevada foothills.

The sheriff said that the flood was triggered by an avalanche on Slide Mountain. The rock and water fell into Upper Price Lake, a reservoir built in the Comstock era. The lake burst its dam, flooding Lower Price Lake, which also burst its dam, and turned normally peaceful Ophir Creek into a torrent that carried boulders and 30-foot trees to the floor of the Washoe Valley.

Six people were hospitalized, including Kathleen Kline, 61, who suffered a leg injury when she was swept from her home by the flood waters.

Her neighbor, Mark Stafford, said that he saw "her head bobbing up and down" in the muddy water. Stafford said he waded over to Kline and pulled her out. She was flown by helicopter to Washoe Medical Center, where she was reported in satisfactory condition tonight.

Stafford said that he and his brother were in a pick-up truck, pulling out of his driveway, "when all of a sudden the trees starting shaking."

He said they got out of the truck just before it was swept into a horse pasture.

Stafford said that he yelled to his mother and sister-in-law, who were in the house, and then he ran ahead of the flood and tried to free his horses, most of which died.

"It was just a wall of trees and boulders and mud," he said of the torrent that pushed its way through the first floor of his house.

His sister-in-law, Marie Stafford, carried four children up to the second floor seconds before the house was hit.

"If the guys hadn't seen it coming, all the kids would have been dead," she said.

The flood destroyed a portion of old U.S. 395 but did not damage the new highway that runs through the valley linking Reno and Carson City.

The break was the latest incident of damage in the waterlogged Sierra, where record winter snows have begun to melt after a week of 80- to 90-degree temperatures.