Yellowstone - Yellowstone National Park became the world’s first national park in 1872. Spanning an area of 2,200,000 acres, visitors need at least two full days just to visit some of its major attractions. Some of the most popular areas in the park include the Old Faithful geyser – truly a feast for the eyes and the soul – and several large hot springs and waterfalls. Roaming the area are free-ranging herds of American bison, Rocky Mountain elks, Grizzly bears and other rare flora and fauna rarely to be found elsewhere.