Campers attending the Montana Wilderness School of the Bible were stuck for two days at the site after three days of heavy rain led to the flooding of a road that was the only exit.
Counsellor Dustin Steele told the AP staff became aware of the floodwaters after being woken up by the sound of water running through two cabins.
"The dryers were going constantly, trying to keep the sleeping bags and clothes dry," he said at the airport in Great Falls, shortly after campers were dropped off and reunited with their families.
"It was hectic, but it was good."
He added that The Montana Army National Guard flew in two Chinook helicopters and made two trips each to airlift everyone out.
Texas was also hit with floods and officials in far South Texas used helicopters to rescue residents from flooded areas.
It is unclear when the campers will be able to return to the school - which has 1.5 million acres of designated wilderness - to finish their year-long course.
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