A new entrance to Onondaga was dug out by Bradford in 1938 (the entrance currently used when entering and exiting the cave). Until this time, tourists entered and left the cavern by boat. Now the tour could be routed so that tourists entered through the original boat entrance and exited by foot through the new entrance. During this same time, Robert Lee Mook was experiencing legal problems. Dr. William Mook's other heirs (who ran the Barnard Hospital in St. Louis) owned shares in the estate, and he attempted to sue them after they had loaned money to Bradford for improvements on Onondaga Cave. Missouri Caverns closed not long afterward because these legal problems as well as decreased interest in tourism during the two World Wars. Cathedral Cave also closed because of the decrease in tourism, and Onondaga's own future was uncertain after the death of Bradford.