This classic of American caving was written by Herb & Jan Conn who, together, spent nealy two decades painstakingly exploring and mapping Jewel Cave.  During that time, the cave grew to over 50 miles of the most intricate three-dimensional networks of underground passages in the world.  Today, Jewel Cave is one of the largest and most beautiful cave systems in the world, thanks to the dedication and persistence of the Conns and a small group of friends.  Complete with maps and photographs, this is a full account of the joys and rigors of discovery. (Cave Books 1981) 238 pgs