I seem to recollect it was in the Mt. Lake area. No gear required, pretty roomy until you got further in. Had to crawl for a while and then reached a small hole where you had to turn on your side, dip your shoulder through, and then pull yourself the rest of the way through. All I could think about was the combined weight of all the rocks sitting above me at that moment. The only reason I went at all was, of course, to impress the girl I was dating. Must have worked - 26 years married and counting.