SEATTLE - Six climbers on Mount Rainier likely perished in a fall after helicopters detected pings from avalanche beacons and spotted climbing gear thousands of feet below the group's last known location, national park officials said Saturday.

Searchers believe the group fell 3,300 feet from their last known whereabouts of 12,800 feet on Wednesday, park spokeswoman Patricia Wold said in a statement. The helicopter crew spotted camping and climbing gear in the avalanche-prone area, park Ranger Fawn Bauer told The Associated Press.

"There's not a viable chance of survival," Bauer said.

Air and ground searches were suspended late Saturday afternoon. The danger of falling rock and ice in the area where searchers picked up the pings prevents a ground recovery effort, Wold said.

"It would expose our rangers to pretty extreme conditions," Bauer said. "And, in all honesty, we may never be able to get on the ground there."

Aircraft will survey the area periodically in the coming weeks and months, Wold said, but the possibility of recovering the six is uncertain.

The missing group includes four clients of Seattle-based Alpine Ascents International and two guides. They were due to return from the mountain on Friday. When they did not return, the climbing company notified park officials, Bauer said.

Officials have yet to finish family notifications, so the names of the climbers are unlikely to be released until today.

"The climbing community is a small one and a close one and a loss of this magnitude touches many," Superintendent Randy King said in the statement.

Mount Rainier, southeast of Seattle, stands at 14,410 feet and attracts thousands of climbers trying to reach its summit every year.

The search for the missing climbers focused on the northwest shoulder of the mountain at the Liberty Ridge area, near where they were last heard from, Bauer said. Saturday's search included a team of three climbing rangers on the ground and flyovers with a Hughes helicopter. An Army Chinook helicopter then joined the search from Joint Base Lewis-McChord.

The group was scheduled to reach the summit of Mount Rainier on Thursday, with a day to climb down.

Snow flurries and hail hit the mountain Wednesday, Bauer said, but the weather has been clear since then.