On the picturesque drive between Butte and Helena, deep in the Boulder Mountains of Montana, near the tiny town of Basin, is a place that for decades has drawn people from around the world for its purported healing properties. Nestled in a canyon, on a heavily-wooded mountain slope, sits the Merry Widow Health Mine. Unlike conventional spas or springs that attract people with the hope of relief from that which ails them, the Merry Widow’s secret sauce has a truly unique key ingredient: Radon. Originally a gold mine, its healing…