I want to know what to look for to know a cave area has been dry for appx 1000 years. LOL
That's a good question. You have to know the layout of the cave and how it relates to where the water is running. You may be 200 feet underground, but if the water never gets above 300 feet, that part of the cave may be bone dry. Given that it may take 10000 years for water to cut through a layer of rock and turn it into a tunnel big enough to crawl through, that bone-dry section of cave may have been like that for a good long time.
I'm not a karst geologist, but the one thing I learned to recognize was a fine, powdery sand/clay mix in these dry rooms. If water hits clay, the clay expands. When it dries, it cracks. It takes a long time for the top layer of clay to degrade so that there is nothing left but dust. That's with no wind, no rain, in the dark for centuries. This is also one of the most stable places in the cave. The room is usually rock solid, because it has no water impinging on it. Rooms like this are preferred for overnight camping and (for the more adventuresome) underground horizontal mamba lessons. You just have to bring a tarp, because that fine particulate gets into everything.
I honestly did not like camping underground. It was a lot of trouble to get a sleeping bag a mile or two back. At 50F and 100% humidity, hypothermia is a constant companion. As far as the other, I had one adventurous cave woman decide to take me to one of those dry rooms. She admitted later that she'd planned the whole weekend just to get me back there. When we got to the dry room, she announced her intentions by dropping all her gear. It was a bit like doing it on the beach.
