Police consider the disappearance a homicide, but family members and volunteers are looking for clues that might lead them to the woman last seen at the Kaiser Permanente hospital in Hayward.
It will take a small group of volunteers about three hours to cover one mile of terrain in Fremont. Before the volunteers set out, they were warned about the risks they were taking.
"(I'm) kinda nervous, 'cause they're saying it's really like unsteady terrain and there's a lot of rocks, and beware of mountain lions," said volunteer Hanh Nguyen.
Still, volunteers like Nguyen continue to show up to volunteer in the search effort for Le, who was last seen in Hayward on May 27.
"I would want somebody to do the same thing for me if I were missing," Nguyen said.
One of the big driving forces behind the volunteer efforts is Le's family -- more specifically, her brother, who refuses to give up hope. The U.C. Berkeley student has dedicated his summer break to finding his sister, and when he does take a rare break, he feels as if he's letting her down.
"I'll take a day just for myself, and I feel horrible," Michael Le said. "I'll feel like I've wasted that day. I know I need it just to stay sane."
Le's efforts have helped raise $100,000 in reward money -- an amount that even surprised him.
"I've never used $100,000 in incentives before, so I hope that's enough to appeal to anyone out there who knows anything," Le said.
The family's dedication has impressed professional searchers, including the Klaas Foundation. The organization agreed to take on this case and help in part because of the commitment from the Le family. The organization hopes more volunteers will commit.
"You can definitely make a difference," Brad Dennis with the Klaas Foundation said. "Volunteers are needed, and this is an opportunity to give back to this family."
"She's the world to me, I can't imagine life without her and living without her has been a struggle. Almost more than I can bear," Le said.
Friday's search was the sixth of its kind, though the group was smaller than previous searches. The family members say they'd like to see more people helping.