Bigfoot

Love bigfoot/yeti/sasquatch/skunkape stories and the classic (now pretty much known to be faked) footage form the Pacific NW footage from the 70s scared the crap out of me as a kid.  Of course, there is no way bigfoot can be real.  There would be physical evidence all over the place.  But here's they way I would write bigfoot in a SF story: they are the remnant of a civilization that predated Homo sapiens. Thousands of years ago, aliens arrived, made contact with them, and befriended them.  The aliens left behind a cloaked space station to watch over them and protect them.  These aliens had the power to eliminate all signs of the bigfoot species existence to H. sapiens. The plot of the story would be that the alien civilization is in decline and has not visited or provisioned the space station for hundreds of years.  There is only one alien left on the station and it is his/her job to continue to protect the bigfoots.  Something like that.