44-year-old Ed Cavanaugh, a teacher in SF's Downtown High School, went missing on July 17 near a cabin where he often retreated in the deep woods of El Dorado National Forest. An avid dirt-biker and survivalist who used survival skills as part of his teaching, Cavanaugh also suffers from Type 1 diabetes, and friends and family members fear that he might have been injured somewhere and unable to get his necessary insulin — though he was known to travel with it everywhere.

As KQED reports, Cavanaugh was last seen on a wildlife surveillance camera on his dirtbike that morning fourteen days ago, shortly after saying goodbye to a friend who was visiting him at the cabin. Since then, hundreds of friends, former students, family members, and concerned strangers have rallied to search the rugged terrain and the warren of biking trails in these woods, so far to no avail.

Also, as the AP reported yesterday, the California National Guard has also brought out their drone to help with the search.

A crowdfunding campaign to help pay for supplies for the search effort has raised almost $60,000. Cavanaugh's sister Karen Cavanaugh describes the search effort as highly committed and organized, but she also describes the difficulty of the terrain.

We group into teams - moto riders, mtn bikers, hikers - and plunge off into the maze of recreation trails that meander throughout the area. It’s a huge area, daunting and seemingly endless.

...It’s vast, thick with foliage, ravines, cliffs, shale, poison oak, blackberries, mosquitos, lions, bears, etc. Can’t stress how thick and steep it is in places…falling into manzanita or into a ravine would hide someone right quick. There are many, many places to hide. Hard to picture until you walk through this forest. One moment I’ll ask myself, how can we not see him or a motorbike? Another moment I’d ask, how could we possibly see him through this forest?

Cavanaugh created the Get Out and Learn program, which he's been leading since 2003, which takes 50 especially truant and at-risk students from the SF Unified system and takes them through a semester-long experiential-learning curriculum that has included boat building and outdoor survival skills.