100k years of strange deaths, disappearances and decapitations. The local Indians think they know why and their story is identical to all other native people who have experienced the same things.
https://books.google.com/books?id=hPST5ZLI4dAC&pg=PA202&lpg=PA202&dq=high+pitched+whistle+from+sasquatch&source=bl&ots=8K0ZWEbIqj&sig=ACfU3U3mj3guDtGhk25VxHyzio8vtsVntA&hl=en&sa=X&ved=2ahUKEwjel-vV9I_2AhUyIkQIHW14CCkQ6AF6BAgREAM#v=onepage&q=high%20pitched%20whistle%20from%20sasquatch&f=false
https://www.oregonlive.com/pacific-northwest-news/2013/01/strange_sounds_coming_from_a_s.html
https://mysteriesofcanada.com/quebec/nakani-the-wildman-of-the-north/
https://www.ctvnews.ca/canada/hunter-captures-strange-howl-in-northern-ontario-woods-1.4686394
https://www.syfy.com/syfy-wire/bigfoot-video-goes-viral