Colorado is a state in the western United States encompassing the southern Rocky Mountains, the northeastern portion of the Colorado Plateau, and the western edge of the Great Plains. The region has been inhabited by Native Americans for at least 13,500 years and has a rich history ranging from the Gold Rush to the railroads. The capital of Colorado is Denver. Characteristic of the state are its breathtaking mountain landscapes and outdoor activities such as skiing, hiking and mountain biking. Attractions include Rocky Mountain National Park, Garden of the Gods, Royal Gorge Bridge, and Mesa Verde National Park, which features ruins of the ancient Pueblo culture.