Earth Angel Radon Mine, Montana

One of six radon health mines in this part of Montana, which apparently are the only active radon health mines in the United States. The Earth Angel, a former gold mine, has the strongest concentration of radon gas, limiting users to 20 visits at a stretch (instead of the usual 30). Halfway down the 600-foot-long tunnel, a fork leads to a narrow, dry chamber, with a few chairs. The main tunnel, paved with concrete, extends further, and has a small stream of water running alongside the walkway. At the end is a chest high dam with a grate on top, opening onto a reservoir - a dark, linear pool of water, plunging deep into the mountain. No decorations at all in this mine.