Which state is home to the famous Yellowstone National Park?

Yellowstone National Park, the first national park in the United States and widely regarded as the first national park in the world, is primarily located in Wyoming. Established in 1872, the park is renowned for its breathtaking natural beauty, geothermal features such as the Old Faithful geyser, and diverse wildlife. While parts of the park do extend into Montana and Idaho, the majority of its area and the most iconic features, including the Yellowstone Caldera, are situated in Wyoming. This makes Wyoming the correct answer for this question, as it is the state most directly associated with Yellowstone National Park's historical and geographical significance.