Grand Canyon National Park authorities are searching for a missing Michigan woman last seen at Mather Point.
Officials say Martha Overholser, 66, visited the park on December 10 as part of a commercial bus tour but left after walking away from the group.
A park spokesperson says they believe she may have headed west from the Mather Point area, possibly towards the Bright Angel Lodge or Hermits Rest.
Overholser is described as a white woman, 5 feet 2 inches tall and 110 pounds, with gray hair and blue eyes. She was last seen wearing a long, off-white coat, a gray hooded sweatshirt and a navy blue-colored bag.
Anyone with information should contact the NPS Investigative Services Branch Tip Line at 888-653-0009 or email nps_isb@nps.gov.