Largest Man-made Geyser
Soda Springs, Idaho
The only attraction in Soda Springs is a unique semi-unnatural feature downtown -- a geyser. It's been there, ready to blast skyward, since 1937 when a local man drilling in search of heated water for a swimming pool penetrated an underground chamber 315 feet down. It was filled with pressurized carbon dioxide gas and water, reaching the surface with a temperature of 84 degrees Fahrenheit and a lot of nervous energy.
The problem was, in contrast to Mother Earth's occasionally well-timed hydramatics -- think Yellowstone's Old Faithful -- this geyser didn't know when to quit. It would spray continuously if allowed, and might eventually exhaust itself. Then what would the town of Soda Springs do with itself?
The Man-made Geyser is now "regulated." A cap prevents it from performing except when scheduled by Man (which is generally every hour on the hour). On windless days, the geyser is reported to reach heights between 100 and 150 feet.
But if the winds are wrong, threatening to blow geyser plumes into streets and businesses, the geyser stays off.
An adjacent covered Visitors Center explains the marvels of the Man-made Geyser with interpretive signs, and a wind meter lets you know whether your visit is poorly timed.
In our case, as we arrived, the Man-made Geyser was gurgling down at the end of an eruption. We didn't have a spare hour to wait, and a guy with a timer key was nowhere to be found.