A seventh person was unaccounted for, the Chaffee County Sheriff’s Department said.
The slide occurred at about 11 a.m. on the trail to Agnes Vaille falls in the Pike and San Isabel National Forest, an easy day hike about a 2 1/2 hour drive southwest of Denver.
A 13-year-old girl was extracted from the slide and flown to Children’s Hospital in Denver, sheriff’s spokesman Dave Cotten said. He didn’t know the nature and extent of her injuries.
The names and hometowns of the hikers haven’t been released. Rescuers from at least five agencies were working at the scene Monday afternoon.
The trail is below Mount Princeton, a 14,197-foot peak. The National Forest Service describes the trail as short and relatively easy.
The trail is one of the first hikes recommended to people new to the area and is also popular with tourists, said Margaret Dean, a regular hiker who has hiked the trail with her 7-year-old grandson.
Dean, a copy assistant at The Mountain Mail newspaper in Salida, said the trail is easily accessible and provides a view of the falls and the Chalk Creek Valley in the Collegiate Peaks, which contains many mountains over 14,000-feet tall.
Agnes Vaille, the waterfall’s namesake, was a Denver mountaineer who died in 1925 while attempting a difficult winter climb of Longs Peak, elevation 14,259 feet.