Ключевые слова: active volcano, beautiful, boiling, caldera, colorful, dangerous, environment, forest, geology, geothermal, geyser, hiking, landscape, mountains, national park, natural, nature, outdoor, outside, preserve, rocks, spring, supervolcano, thermal, tourism, travel, travel destination, united states, usa, vacation, vacation destination, vapor, volcanic, volcano, water geyser, wilderness, wyoming, yellowstone, yellowstone caldera, yellowstone national park,