Not much that I can do to help you. The mix of deciduous, conifers, limestone karst and steep shaded cliffs makes for a daunting task. It may have fallen into a deep crevasse that would make it impossible to see by air. I have been reading about the park for hours now. You have a very big task ahead of you. It is a very dangerous place. There are no local rescue teams and yet they want to promote tourism. There is no way to protect nature from hoards of tourist wanting souvenirs. Well, I read the book, I can't wait to see the movie.