St. Mary Falls, Glacier National Park/Rebecca Latson

Editor's note: This updates with identification of the victim and the National Park Service correcting details of the incident.

A Pennsylvania woman drowned at Glacier National Park in Montana when she fell into Virginia Creek between St. Mary Falls and Virginia Falls and was swept over the falls, according to park staff.

Gillian Tones, 26, of North Apollo, Pennsylvania, slipped on wet rocks Sunday evening and "was quickly swept up by the cold, fast moving water and went over a series of smaller waterfalls, then was pinned underwater by a log for several minutes until heroic efforts by other park visitors led to pulling her from the river."

Despite resuscitation efforts by bystanders, park rangers, ambulance personnel and ALERT helicopter medics, Tones never regained consciousness and was pronounced deceased by ALERT personnel at about 7 p.m. on Sunday.