Crews focusing on possible gaps in search for missing 79-year-old San Mateo Co. hiker

PORTOLA VALLEY, Calif. (KGO) -- Monday marked day five for volunteer search teams in Portola Valley, looking for 79-year-old Margaret Elaine McKinley.

Around 60 people spent all day in the Windy Hill Open Space Preserve, the last known location of the Redwood City woman with Alzheimer's.

It's seemingly impossible to remain optimistic when a loved one is missing - a reality that Kit Durgin now knows all too well.

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But as crews remain searching for her longtime partner, positivity remains the driving force.

"I'm living on their hope," Durgin said. "They tell me that a very high percentage of their searches end up successful. But it's devastating. It's very easy to go back and think about what I should have done."

McKinley has been missing since Thursday, when she, Durgin and a friend were hiking the Lost Trail in the Windy Hill Preserve.

They were only a quarter mile from the car when the group lost sight of McKinley.

Professor Xeno Rasmusson of Human Development from Cal State East Bay said there is a chance of a decline in mental abilities because of her Alzeimer's.

"She's going to have a problem with decision making, route finding, even if she's familiar with those trails it's not going to be the same thing," Rasmusson said.

Officials part of the search said they remain hopeful.

Including Elaine's longtime partner and caregiver.

"For anyone with dementia, and especially for caregivers I do think I think it's important we empathize with what they go through and I think it's important that for Elaine's caregiver that she gets support and people don't question how if she was irresponsible with this decision," Rasmusson said.

More than 500 total volunteer searchers have been working ever since, covering 4,000 collective miles across the expansive open space preserve.

"First, early phases are more hasty and we're running trails and more obvious places where a person might be," San Mateo Co. Search and Rescue Volunteer Ray Kruk said. "So now, we're looking at the places where a person might leave a trail and go, hunker down and maybe stay warm at night."

Air support, K-9 units, horses, and even ATVs are all being utilized in the search.

Neighbors in the area are asked to check any cameras for leads - McKinley was wearing a red jacket, black pants and a backpack.

With no luck thus far, teams in the field deployed a new strategy.

"Our volunteers have brought out chainsaws to help us clear out some of the dense brush, so we can start double-checking over some of the gaps that we might have had to pass over before," San Mateo Co. Sheriff's Office Sgt. Philip Hallworth said.

The weather is warm, and there are rattlesnakes and other factors that make it hard on the all-volunteer search staff. A sheriff's deputy said poison oak is as tall as fifteen feet.

But no matter the conditions, hope pushes everyone forward.

"Everyone's motivated, everyone is going as if it's day one," Kruk said. "So, it's just a matter of time, hopefully, that we can find her."

Despite this going into day five, it remains a search and rescue and not a recovery effort, according to the Sheriff's Office.

ABC7 spoke with Elaine's longtime partner, Kit Durgin who was at the command post Monday evening.

She didn't want to go on camera. She said she went searching for Elaine with a psychic and her therapist. She said she's ending the day on a low note, but will be back here Tuesday morning.

Everyone, ourselves included, is hopeful Elaine will be returned to her family soon.