Rescue workers are now searching hundreds of caves across the Craters of the Moon National Monument in the hunt for Amy Linkert, 70, who has been missing since Sept. 19, The Idaho Statesman reports.
Linkert and her companion, Dr. Jo Elliott-Blakeslee, 63, were hiking along the park's Tree Molds Trail. Elliott-Blakeslee's body was found Sept. 25 in a lava field roughly a mile from the trail, but there is still no sign of Linkert.
In the wake of inclement weather, the search for Linkert has shifted to a vast network of caves under the lava fields, where she may have sought shelter.
"That's the most likely place for Amy to be if she's sheltered up, is in a cave somewhere," said Traci Weaver, public information officer for the National Park Service.
Currently about 45 people are combing the park for Linkert, including two experienced cavers and seven search and rescue dogs.