I heard about David Paulides on the mysterious universe podcast last year and I've been hooked ever since. I've spent entire weekends listening to his interviews. The missing persons cases are incredibly baffling and don't fit any kind of normal profile you would expect from people going missing in the woods. Stranger yet, they happen in specific area 'clusters', and national parks don't want to touch this with a 10 foot pole.
I would love to hear Erik's take on this phenomenon.
Here is the main website http://www.canammissing.com/missing_411.html
Also, go on Youtube and type in Missing 411, basically any of David's interviews will have you hooked.
And a PSA - DO NOT buy his books from amazon, they are from a reseller who price gauges.