The Yellowstone National Park in the morning twilight. The Lower Yellowstone Falls drops 94 m (308 feet) and the Yellowstone river continues in a colorful valley known as the Grand Canyon of the Yellowstone. The colors in the canyon are the result of hydrothermal alteration. Established in 1872 the Yellowstone is the world's earliest national park, located in Wyoming, USA, known for its wildlife and geothermal features.