It boggles the mind that something that massive didn't get picked up sometime, especially in this age of broadly accessibly high quality satellite imagery.
Quite likely. I have no idea why this was downvoted. It's usually the case native populations had far greater knowledge than they are ever credited for. Perhaps they will find some evidence of humans inside.
It's quite possible that the indigenous population knew of the cave, but it's very unlikely they ever purposefully descended into it. There's not much reason to, and it would be a very difficult descent.
And yet when my acquaintance summited Mt Everest, there was a Tibetan native there in a fur suit and hat.
I am almost certain that there will be evidence of native incursion into the cave. Its been there a long time; the natives have been there a long time. Young bloods with nothing to lose are always doing damn-fool things like that.
There's no evidence that Sherpas summited Everest prior to Norgay doing it with Hillary's expedition. Into The Silence covers this in more detail, if you care to read the whole book, but there were technological and cultural hurdles to it ever happening.
Everest is a pretty clear example of native people not bothering to do stupid things until white people show up and get them tangled up in the mess.
From what I have read they were pretty far up but there is a pretty hard limit to what you can achieve without technology. There is a huge difference between climbing to 8000m vs 8800m.
Technical detail (who was first to the tippy top). Sherpa's were climbing the mountain for centuries. Somebody has been in that cave, because its there.
No kidding. Just the Wawa-Sault Ste. Marie-Timmins-Sudbury quad is large enough to be lost in for several lifetimes. One tell that you are about to enter uncharted territory is a sign that reads 'last gas station for 400km'.
And that is one of the more accessible areas, there are still plenty of lakes where a water plane can land and there are logging trails every 30 km or so.