How could a 8 foot plus primate that weighs hundreds of pounds be able to stay so well hidden for 400+ years?  The answer to that is where they live and tunnel vision that most people have of their environment.  This primate has been seen but on rare occasions by a lucky few.

The first 300 years we have some journal entries, stories about ghosts/hermits/monsters and oral history about this primate.  In the 50's stories starting to catch the media attention about Big Foot.  Most areas where they live is rugged and remote.  It was not until we started to live in these areas or to use these areas that more reports started to surface.

They like to stay in the shadows and to stay hidden.  Our military also has perfected the art of camouflage.  Men can literally hide in 10 inches or less in foliage and be never seen.  Why wouldn't another primate that is human smart be able to stay for the most part hidden from us?  I think some are hiding in plain view because of our tunnel vision. 

Just because we can't see something doesn't mean that it is not there.  Mysteries still abound in our world and we need to stay open-minded and be willing to explore possibilities.