There has been talk of opening other parts of the cave for years, the problem being areas like the lakes passage can only be accessed by crawling through long passages, dropping down several drops, only to end at the grand cravas, two narrow walls you must chimney down. All that to get to the lake. One you are there its cool though. Mystic river is a mud crawl that just keeps getting smaller, and lost river passage behind the dam is structuraly unsound do to the flooding and pressure from the water. Short of dropping an elevater to the lake like blanchard springs did, It would be difficult to add a commercial tour.