Yellowstone National Park, Wyoming
You may have seen Old Faithful blasting into the sky in August. But have you ever witnessed this monster geyser shooting up white mist into the frosty winter air?
Each year, more than 4 million people crowd the roads in Yellowstone National Park, one of America's crown jewels. Few of them will leave the pavement — and almost none of them visit during winter. They are, in a vast understatement, missing out on some of the best the park has to offer.
For instance, in winter, the park's famous geysers blast near-boiling water that freezes almost immediately in the air and falls as unique "geyser rain." Herds of animals like elk and bison cluster ever closer together for protection and are easier to spot in the white of deep snow drifts. Ice skating, snowshoeing and cross-country skiing are also popular in Yellowstone.
The frigid Western weather drives away the masses, and lodging is scarce, so there are no traffic jams or long lines. In fact, normal civilian traffic is prohibited from park roads from November to March, meaning visitors must take snowmobiles or snowcoaches to access Yellowstone [source: NPS].
If you're daring, fit and prepared, you can even opt for backcountry camping during the winter season. You may find that you have millions of acres of Yellowstone's majesty all to yourself.