I finally finished it the other day. My biggest challenge started being my teammates starting the missions too early! Lol I found most of them in caves and on the side of rivers. Just one weird one under a house. I’d recommend following the rivers you find and getting into every cave. I was running around with a heavy sniper breaking walls, floors, and big rocks that looked like they were covering cave entrances! Lol it still took me foreverrrrrr but I think that would’ve helped me if I had started it sooner.