Frappier contacted park rangers with his cellphone Tuesday night, telling them he got stuck on a ledge as he was descending from the summit of Longs Peak, about 120 kilometres northwest of Denver.
Officials in Colorado say he was climbing with a friend, but the two became separated during their ascent.
Frappier was descending when he became stranded on Broadway Ledge, and called for help from his cellphone.
“He is in an extremely precarious location on the east face of Longs Peak at roughly 13,000 feet in elevation. Samuel did not report any injuries but indicated he could not go up or down,” officials from the Rocky Mountain National Park said in a statement.
The ledge, about 4,000 metres high, can receive wintry weather including significant snow and ice.
“Fortunately there was no moisture overnight.…The young man is reported to be physically fit, but has no technical climbing equipment and is an inexperienced mountaineer. He was not prepared to spend the night,” the statement said.
A technical rescue team arrived on site Tuesday night and set up to carry out a rescue operation today.
Officials say the 28 rescuers involved are dealing with hazards such as falling rocks and ice.