Body of seventh hiker found in Zion National Park in Utah

Park officials said all seven were hiking together on a day trip through narrow Keyhole Canyon

Search teams have found the body of a seventh hiker killed in a rain-swollen canyon of Utah's Zion National Park hours after the ill-fated group obtained a park permit to venture into that area despite forecasts of probable flash flooding, park officials said on Thursday.

The seven canyoneers were swept to their deaths late Monday afternoon during a flooding that killed 12 people and left two others missing elsewhere in southern Utah, most of them in the town of Hilldale on the Arizona border.

The body of the seventh and final member of the canyoneering group missing in Zion was located on Thursday, capping three days searches by more than 60 park rangers, sheriff's deputies and emergency personnel from several agencies.

The names of the seven victims, who ranged in age from their mid-40s to mid-50s, were being kept confidential until next of kin were notified.

Park officials said all were visitors from California and Nevada hiking together on a day trip through narrow Keyhole Canyon, a challenging route on the east side of Zion that requires canyoneers to swim through several pools of water and rappel steep slopes.

The leader of the group had experience exploring that canyon and others, said Cindy Purcell, Zion's chief park ranger.

The group obtained its permit for the trip at 7:30 am Monday, even though they were advised the National Weather Service had forecast a 40 per cent chance of rain and the probability of flash flooding in the park, Purcell said.

"The ranger who handed that permit to that man said, 'I would not go today,'" Purcell said. "However, the people who go make the choice, they sign the paper that says that it is their safety and their responsibility."

Purcell said park rangers would only decline to issue a permit in the event that an official flash flood warning was posted. The National Weather Service did issue such an advisory that day but only after the seven canyoneers had already set out on their venture, she said.

Keyhole Canyon permits were issued that day to two other groups, Purcell said. One canceled and the other, a group of three, started before the seven-member team but passed them and made it out safely, she said.

Nearly an inch of rain fell on Zion in less than an hour on Monday, swelling the North Fork of the Virgin River, which Keyhole Canyon drains into through two tributary creeks, from 55 to 2,600 cubic feet of water per second.

Flash-flood fatalities are rare in Zion, which is visited by more than 3 million people a year.

This week's deaths marked the greatest loss of life in Zion's history, surpassing a 1963 tragedy in which five people were killed by flash flooding in the Virgin River Narrows, Purcell said. Since then, floodwaters have killed six others in the park, most recently a man drowned in 2014, she said.