The phenomena surrounding missing people (actively missing, later found, and cases involving a death) within national parks (but not limited to)

I listen, read & watch so many things day after day/week after week it's hard to keep it sorted in my mind.  I remember somewhere that there is a DNA component to the alien type abductions, something about austria/german/bavaria area DNA and Elk hunters in Utah.  One UFO abductee was returned to earth after they told him ' you're not exactly what we needed' he (abductee being returned to earth) perceived that had taken others humans previous to him being stolen while hunting, to another planet to seed a colony elsewhere, but the aliens wanted a specific strain of human DNA.  I have also heard of the portal theory.  I think 4th dimension reptiles eat some people as snacks, especially near mountains/caves.  It's a good question to ask..

@chelsb23 Good question! Thank you for posting!

I've also often wondered! How do expert climber/hikers disappear without a trace on a mountain or inside a cave? Then there are aerial disappearances, like the case of the senators whose plane disappeared in Alaska and no wreckage was ever found. I wonder if ground, sea, and air disappearances/phenomena are all attributed to the same root cause or if different things are at play. 

@marina_doktor  David Paulides and his Missing 411 books and videos are superbly interesting.  I remember one case near the Superstition Mountains in Arizona, a man claimed to be walking down a trail back to his vehicle and the path 20 feet away, in full sun, appeared to 'shimmer' as if it was some kind of something.  He got a bad feeling and walked in a big arc AROUND it (it was like a barely visible doorway, just a slight shimmering in the air gave it away) which was difficult to do because of the mountainous terrain.  He commented later if felt if he walked into it, he would have come out of it.  Then there's the case of the child taken from an unlocked truck, while strapped into his child seat.   Middle of no where.  Father got out to scout a fishing spot, comes back, kids gone.  He was 18 months, no way he could have opened the buckles by himself.  I think there are portals that can be opened at ground level & sky level, which explains why toddlers are found 20 or 30 miles away from where they disappeared.