Most of the pic's show a shortage of trees around the cave. Was there other vegetation like brush that they used for the firewood or was there, at one time more trees and they were used up for cooking?
This is the valley below Castle Rocks. Its like a high desert with an aluvial glacier plain. Many of the native plants can be found only here and nowhere else in the world. There are lots of trees just not in this area. It gets lots of snow melt. The water is also very cold. Great Brown Trout fishin!