Established in 1872 as the world's first national park, Yellowstone spans 2.2 million acres across Wyoming, Montana, and Idaho. It sits atop one of the largest active supervolcanoes on Earth and fuels over 10,000 hydrothermal features—including more than half of all the world's geysers. Yellowstone is bear country. This is not something many people really come prepared for, so to keep it simple, stay 50 yards (2 buses) away from herbavores, and 100 yards (5 buses) from omnivo