In the face of grueling conditions in the remote and sweltering Mojave Desert, hundreds of Search and Rescue volunteers made it their mission to find Erin Corwin.
"The terrain was rough: sharp rocks, cactus," said Sonny Lawrence, one of the members of the Search and Rescue team.
"The temperature the first day out we hit 117," said Doug Billings, a mine expert who specializes in the area around Joshua Tree.
When evidence came forward Christopher Lee had searched online for how to dispose of a body, detectives tapped Billings for his 35-year knowledge of the area's mines. He's mapped many of them himself and developed a search program for the investigation.
"I didn't have to look at a map. I knew where I was at any time in any of the mines so I was able to direct the rescue team," Billings said.
Days began as early as 3 a.m. and the fragile state of these old mines posed dangerous hazards to searchers.
Time was their enemy.
"This is fast pace, to search as many as we can in the shortest amount of time," Billings said.
"Some of us became pessimistic, I know I did," Lawrence said of the weeks long search. "It's difficult to keep the enthusiasm up."
Eight-five mines were thoroughly searched before finding the one holding Erin.
Lawrence was the team leader of the Search and Rescue crew for the Rose of Peru mine.
"It was a 10 by 10 hole that went down," he said. "It was vertical for 45 feet and then it started sloping."
Cameras couldn't reach the bottom of the slanted cavity, so one searcher descended into the darkness and discovered her body.
"One of our team members had to go down on rope and get close enough to Erin to be able to identify her," Lawrence said.
"I just said Thank God, it's over," Billings said.
Now there's a petition to close or fill abandoned vertical mineshafts in California. More than 400 people have already signed, including Erin's husband Marine Cpl. Jonathan Corwin.
"They should be closed for the safety of everybody, and this just tops it because nobody should have to wonder if a loved one is at the bottom," said Aisling Malakie, one of Erin's close friends who signed the petition.
But those familiar with the mines adamantly oppose the idea, saying the mines are historic and provide a habitat for wildlife.
"These mines did not kill anyone. It's just a hole in the ground, that's it," Billings said.