Have you seen the threads on the radon mines here at KA??
That is where I learned about it and found out the Montana one was a four hour drive from my house. I had a 5 week remission starting on around my 2nd day there. My one and only remission.

If you have the opportunity, I WOULD GO IN A HEARTBEAT! I've read online about the ones in Austria at Bad Gastein. There are a couple of people here on KA who go every year, and that is their ONLY treatment for AS. I begged for my family to go to Montana again this year for fall vacation, but alas, I lost and we went to Bear Lake instead. Which was fun, but I didn't get a remission if you know what I mean!! lol. The owner of the Montana mine told me I really should have come back six months later for my 2nd visit and then I would have likely been in remission for 9-12 months. At the Montana mines, you only breathe the air and drink the water. In Austria you sit nearly naked down in the humid steamy mine and have treatments emerged in a full bathtub of water drawn from the mine. So the "real" radon spa experience exposes you to more of the radiation. I am still very grateful for my Montana experience. I read a book by Ed Hiserodt called "Underexposed, what if radiation is really good for you?" That put my fears at ease about the toxicity of ingesting radon on purpose.

Sorry for the off topic-ness. I should have sent this in a PM!

Take care,