Grand Canyon evacuations halted after dam breach

(CNN) -- Authorities halted the evacuation Sunday night of a few hundred people who were initially thought to be in danger after rain breached an earthen dam at the Grand Canyon.

Rescue crews in helicopters evacuated about 170 people Sunday after water poured through Redland Dam, sending water down two canyons and threatening several hundred tourists and residents, said Gerry Blair, spokesman for the Coconino County sheriff's department.

A few hundred others were not evacuated, but they were on high ground and did not appear to be in immediate danger by Sunday night, he said. Authorities plan to decide Monday whether to evacuate them.

They also plan to resume the search Monday for "less than 20" people who were in the affected area and whose whereabouts are not yet known to authorities, Blair said.

The air evacuations were called off due to darkness at 8:30 p.m. Sunday (11:30 p.m. ET). iReport.com: Are you there? Send photos, videos

Most of the 170 people evacuated Sunday were campers, tourists and paddlers, he said.

A few hundred others -- perhaps as many as 400 -- remained in the area of concern. Most are permanent residents of Supai village, located within the Havasupai Indian Reservation at the bottom of the Grand Canyon.

They were on relatively high ground and were not in immediate danger Sunday night, he said, but sheriff's deputies, U.S. Marshals and officers with the Bureau of Indian Affairs police force were taken by helicopter to the village. They plan to stay at least until Monday.

The problems started when water breached Redland Dam and poured into Cataract Canyon and Supai Canyon, which was heavily flooded, said Blair said.

Rescuers used five helicopters -- three of them Black Hawks -- in the rescue mission. Evacuees were taken to a Red Cross shelter at Hualapai Tribal Gymnasium in Peach Springs.

Blair said visitors who hike down into the canyon are required to register with authorities. Authorities have accounted for most people in the area.

Earlier, a private boating party of 16 people was stranded, but uninjured, on a ledge at the confluence of Havasu Creek and the Colorado River on Saturday night after flood waters carried their five rafts away, authorities said.

Geoff Gourley, a veteran river guide at the Grand Canyon, told CNN that campers on multi-day paddling trips often park their boats at the narrow mouth of Havasu Creek to hike along scenic ridges of the side canyon. Watch how flooding surprised canyon residents, visitors »

While he couldn't comment on the 16 campers, he said heavy rains from as far as 15 miles away can wash into the Havasu, swelling it enough to flush the boats down the river.

"I imagine that's what happened here," Gourley said.

The waters of the Havasu -- normally a brilliant blue-green -- churned a muddy red Sunday. A flash flood remained in effect Sunday evening and more rain for the area was likely, the National Weather Service warned.

Tourism is the main source of revenue for the Havasupai reservation, which was created in 1882.

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