Dwight Deal, Jan and Herb Conn in the Visitor's Center of Jewel Cave National Monument in 1989 on the 30th anniversary of the Deal-Conn exploration effort (50 miles in the dark). Note in the background, that Jewel Cave was always running off of Herb's maps of the cave. No sooner did the Park Service put up this nice map display of the cave, the cave allowed exploration to take off to the west.