Yellowstone was established on March 1, 1872. It is the world's first National Park.
Yellowstone became a national park almost 20 years before Wyoming, Idaho, and Montana became official U.S. states.
Yellowstone is larger than the states of Rhode Island and Delaware combined.
In the park's early days, visitors came to watch bears eat garbage
There are more than 300 active geysers and more than 290 waterfalls.
Yellowstone's hot springs are so hot and acidic that they can dissolve a human body in a single day. In 2016, a visitor fell into a Yellowstone hot spring, and 24 hours later, his body dissolved.
Yellowstone is home to the oldest log cabin building in the world. Called the ‘Old Faithful Inn’ it was built during the particularly bitter winter of 1903-1904.