The search for missing Berkeley man Philip Kreycik is set to resume Saturday, three weeks after he went missing while on a run in Pleasanton Ridge Regional Park.

Volunteer searchers have been steadily scouring the park area all along, but the official search was scaled back and largely stopped after eight days and no useful leads. As SFist reported last week, Pleasanton and Alameda County authorities have called the case baffling and unprecedented, and despite the use of a heat-seeking drone camera, tracker dogs, and the efforts of hundreds of people, there has been no solid clue as to where Kreycik may have ended up.

He disappeared after saying he was going on a one-hour run in the midst of a heatwave on Saturday, July 10. While there had been some suggestion that Kreycik was an experienced ultra-marathoner who was experienced running in hot weather, friends have since said that Kreycik likely wasn't conditioned for the heat that day, having spent most of his time running in the East Bay's temperate conditions. The high temperature in Pleasanton reached 106 that day.

The Pleasanton PD announced on social media Friday morning that the search would resume in earnest this weekend. And as Sergeant Ray Kelly with the Alameda County Sheriff’s Office tells the Chronicle, this search will focus on "the deep ravines, creek beds and water runoff areas" in the park.

"Let’s bring some closure here, so that his family has the answers they deserve," Kelly says.

"Though efforts have scaled back, both the search and investigation remain underway," the Pleasanton PD writes on Facebook. "Tomorrow, members will return to where Philip intended to run and comb select areas in hopes of bringing him home. We will provide an update after the search is complete."

Chris Thoburn, a friend of Kreycik's who had gone running with him just the day before he disappeared, did an AMA (ask me anything) about the search and his friend last Friday, and here's what he had to say about the heatstroke theory to his disappearance:

"Philip was NOT heat adapted. He lived on the Oakland/Berkeley border and most of his training was on the Bay side of the ridge. This means he rarely ran in temps above 80, and morning and evening runs (where he typically had time) would have been in the 50s or 60s. Unlike many athletes he ran with (including myself) he wasn't intentionally heat training. Philip does not race, he just enjoyes [sic] running and is very good at it, so there wasn't the same motivation for that which others do have."

And further supporting this theory...

"Irrational decision making is probably the most common heat symptom I've observed. Things like running the same 50' section of trail back-and-forth during a race, or choosing to retrace steps for miles instead of continuing a short distance forward to safety. Someone with heat illness might choose to wander in sunlight when the rational decision would be to seek shade, and they usually do not recognize that their decision making is compromised...

"A great story I heard this week comes from a runner I know who suffered heat exhaustion earlier this year (and who thankfully had his phone, had water, and was in familiar territory). He was only 15min past his last stop for aide and supplies when he realized he was cooked. So he sought shade thinking he'd cool down for a bit. He sat there for almost 4 hours, watching hikers go by who didn't ask him if he needed help, nor asking them for help. He eventually texted his wife to pick him up only a mile away (downhill), and it took him nearly 2 hours to make that descent because of his need to pause for rest and bring his heart rate back down."

Thoburn also says that much of the search in more recent days has been focused on looking for odors and "smaller parts" assuming that Kreycik's remains may have been already compromised and/or partially buried by wildlife. Adding to that theory, multiple mountain lion sightings were reported in the area in the early days of the search.

"It's far more likely that he either succumbed to the heat or fell prior to any wildlife involvement," Thoburn says. "I say wildlife because it's not just mountain lions that might opportunistically feed on someone that's incapacitated in the park: coyotes, bob cats, vultures, and wild hogs are in these hills."

Previously: Still No Trace of Missing Berkeley Runner Philip Kreycik; Detectives Call the Case 'Baffling'