DENVER – A woman is recovering after she was struck by and trapped under a 1,500-pound boulder while she was hiking west of Denver.

The Denver Post reports the 30-year-old woman’s legs were pinned for more than two hours under the boulder at the popular North Table Mountain Park in Golden on Wednesday. Rescuers used a hydraulic system to free her.

The woman, who had multiple fractures and was unconscious, was flown to a hospital in critical condition, according to the Golden Fire Department. Her name was not released, but the Fire Department said she was visiting Colorado from Europe.

Karlyn Tilley, a spokeswoman for the Golden Fire Department, says a man hiking with the woman told rescue crews he heard a loud crack and saw the boulder break loose.

About a half-dozen agencies assisted in the rescue, the Fire Department said.

Rockslides often occur during the spring freeze-thaw cycle, and large boulders can break free from mountainsides during drastic temperature changes.