Jewel Cave Adventure: Fifty Miles of Discovery in South Dakota
"Destined to be one of the very few classics of American caving." --NSS News"What a tremendous undertaking it was and what persistent work the Conn's performed. The story is a fine piece of understatement [about] the physical struggle and the down-right agony involved in the miles of crawling necessary." --Russell H. Gurnee, Past-President, Explorers Club; Past-President, National Speleological Society