Yellowstone National Park is the oldest national park in the United States. It was established on March 1, 1872. The park is located in the western United States, primarily in the state of Wyoming, and also extends into Montana and Idaho. Yellowstone is known for its wildlife, including bears, wolves, elk, and bison. The park also has many geysers, hot springs, and other geothermal features.

Here are some interesting facts about Yellowstone National Park:

* Yellowstone is the largest national park in the contiguous United States, with an area of over 3,400 square miles.

* Yellowstone is home to more than 290 species of birds, 67 species of mammals, 16 species of fish, and 1,100 species of plants.

* Old Faithful is the most famous geyser in Yellowstone. It erupts about every 91 minutes, sending water and steam up to 184 feet into the air.

* Yellowstone has the largest concentration of geysers in the world, with over 500.

* Yellowstone is also home to the Grand Canyon of the Yellowstone, a 24-mile-long canyon with walls up to 1,200 feet high.

* Yellowstone is a UNESCO World Heritage Site.