The search for 15-year-old Sierra is getting more difficult, both physically and emotionally.
"I'm worried about finding her body," volunteer searcher Mary Kamakani said. "I don't think she's staying anywhere on her own free will, if she is still alive."
Kamakani's team is in South County near Betabel Road. The weeds are as tall as the volunteers, and the odds seem just as daunting.
"You can't think about terrible things," volunteer search leader Wayne Rhoten said. "You have to get the job done, get serious here."
For sheriff investigators, serious means revisiting waterways. They're reviewing underwater sonar images taken Tuesday at Uvas and Chesbro reservoirs. They are close to Sierra's home where she disappeared on March 16.
"Depending on if any suspicious objects or items come up on these sonar imagery, they will send divers in the next couple of days," Sgt. Jose Cardoza with the Santa Clara County Sheriff's Office said.
The sheriff's office plans on sending out deputies on dirt bikes to some of the remote areas. Some of the community volunteers are also covering some of the rugged terrain.
Despite the obvious fears about how the search for Sierra ends, there is no one at the search center giving up, least of all Sierra's mother, Marlene LaMar.
"I am not losing hope," she said. "I am not losing hope and I never will."
Some of the volunteer searchers know first-hand surviving an abduction is possible. Frank Harper of San Jose rescued a young woman from a field near Gilroy in 1999.
"Before I could even get out of the van to try to help her, she's up to my window and saying that she'd been kidnapped and raped by these three guys," Harper recounted.
Thanks to his help, the men involved were found and convicted. Now Sierra's family and an extended family of volunteers are pleading for their happy ending.
"If she is with someone, please let her go," Kamakani said. "Her family needs her and she needs them."
The sheriff's office says it appreciates the volunteer searches which are augmenting their own official efforts. Hundreds of volunteers are expected again this weekend.
The family has launched an official website, FindSierraLaMar.com, in conjunction with Child Quest to help volunteers and anyone else interested in following the search for Sierra.