YELLOWSTONE NATIONAL PARK--If there's any doubt that more visitors to this treasure of nature check out Old Faithful than anything else, all you need to do is compare the size of the world-famous ...

Yellowstone National Park is considered a national treasure. Not only is it the first national park ever established anywhere in the world, it's also filled with an amazing array of natural features.

Though they are considerably less glamorous than the hot geysers you may have seen in Yellowstone, sewer geysers are worth paying attention to because they are symptomatic of a 19th-century design ...