If you told your friends or family that you were going to spend some of your vacation in an active volcano, they might think you were crazy. Yet every year more than three million people do exactly that. Yellowstone National Park is a volcano. Almost everything that is special in Yellowstone is the result of being one of the world’s largest active volcanoes, in fact, a super-volcano. Fortunately, Yellowstone’s current volcanic activity is limited to hot water and earthquakes -- no eruptions, flowing magma, or cataclysmic explosions. Yellowstone did the cataclysmic explosion thing about 640,000 years ago and is resting for a possible encore in some more tens of thousands of years. Yellowstone the volcano is not going to erupt anytime soon.

What you will see of Yellowstone’s volcanic activity are hydrothermal features -- geysers, fumaroles (steam vents), hot pools, mud pots –- a collaboration between water and the heat of volcanic material far below the surface. Half of all the world’s hydrothermal features are in Yellowstone –- one half. There are geysers elsewhere, Iceland and New Zealand for example, but nowhere else is there such a concentration and diversity. If this was all there was to Yellowstone, it would still be a very special place.

Yet even if there were no hydrothermal activity, no Old Faithful Geyser, the list of superlative natural features in Yellowstone Park is impressive: One of the world’s most spectacular canyons (including two extraordinary waterfalls) cut deep into the gold-weathered volcanic rock of the park; the world’s second largest high altitude lake nestled in the pit of the Yellowstone caldera; magnificent mountain scenery ringing the unique terrain of the Yellowstone volcanic plateaus, and last but not least, one of the most important concentrations of wildlife on the planet.

In 1872 Yellowstone became the world's first national park, a tribute to its uniqueness. Today, though surrounded by challenges of many kinds, it remains one of the great natural wonders. What kind of a destination is Yellowstone? A very, very special destination.

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