In addition to what I said above, I tend to think of Bigfoot as something primitive, primal, and VERY in synch with nature.
I know there’s a lot more to U.F.O.s than metal craft and technology, and I know that both Sasquatch and U.F.O,s involve dark, starry nights, secrets in the woods, legends whispered around campfires, and that both Sasquatch and U.F.Os have some interdimensional science and some ghostly qualities. But Sasquatch definitely has earthly properties and not that technologically advanced.
Where they overlap (Sasquatch and U.F.O.s) may lie in the theories about ancient astronauts (the Annunaki) doing genetic experiments and breeding on humans, especially in ancient times—and their coming again, if they never really left.
Sasquatch could therefore be something they brought with them to breed with us, or we are something they selected out of them, or something they found here that they bred us from. Or both could be something of the “watcher” genre in Jewish mysticism or the Book of Enoch.
Avenues to explore on the internet about these topics include Annunaki, Book of Enoch, Watchers—in various combinations with Bigfoot and U.F.O.s