Thanks so much guys. I'm sure there is a lot of clean up that had to be done, and I have no doubt my large 530 MB file probably needs a LOT of clean up as well. I just don't know enough on how to smoke out those problems and how to do it.
I did experiment with it further and found the problem. There are way too many points in the curves. My intention was to pull it down five feet, scale the bottom face down some, rotate it some, and then repeat to create the bottom of the cave structure, but the program absolutely wouldn't tolerate that. Whenever I try to do any kind of maneuver on it such as scale, intersect faces, rotate, etc., that's when it shuts down. I got around it by pulling it down into a solid 5 feet down (It would allow that) and then on the bottom edge I started combining the points into a much more simplified pattern, which of course is a cruder representation of the curves, but for my purposes is sufficient. The cruder curves had only about 10% of the points the original curves had and as long as I worked with those points and left the original curve alone, the program wouldn't shut down. I could pull down further and work with that to create my cave structure. It seems that for any individual operation, if the number of points and/or faces exceeds a certain number, the program will shut down. Coding-wise, it acts like an informational storage stack problem.
I'll take a look at the files you guys posted and see how I can use those. Thanks so much guys. Much appreciated.