Also in Africa were stories of elephants that live in forests (the forest elephant). The more common African Savannah elephant was know n for centuries, but stories of elephants in forests were taken by zoologists as impossible (the natives must have been high). What they didn't know is that elephants have a very soft pad under their feet, and can veritably walk in undergrowth while making very little noise. It is almost eerie.
Anyways, Sasquatch is probably imagination only. However lack of photographic evidence or bones is not proof positive 'something' is not there. It is extremely hard to find the remains of wild animals in any wilderness. Even a domestic cat (unless immediately killed by a car) will not normally be found.
There are documented cases of feral children,, including one young girl who was captured - but then escaped!
She was seen a few years later, but never captured again.
And most of these cases are in Europe - France and such - areas that are a whole lot more civilized and logged and open than the American west.
It is odd that you feel that way, especially since the Injuns ALL admit to Sasquatch, dating far before the establishment of the US. I know these folks first hand (Salish (Kootenai), Flatheads, Blackfeet, and a few N.Cheyenne). Why are these natives' observations discounted?
And I can personally attest to the bare fact that my own eyes have witnessed more than 'imagination'.
There was a dead rabbit on our driveway. In two days, there was nothing left but bones. The third day, there was no trace left to show that the animal had ever been there — even the blood stain on the concrete was gone.
I wish I had time-lapse/motion detection video recording capability, for I would love to have seen all the creatures and insects that dined on the bunny.