Ключевые слова: active, america, americans, attraction, building, center, ecosystem, education, exterior, faithful, first, geothermal, geyser, idaho, information, montana, national, native, nature, north, old, oldfaithful, oldfaithfulvisitorcenter, outdoor, park, preserve, service, spring, states, thermal, tourism, tourist, touristattraction, travel, united, us, visitor, volcano, wyoming, yellowstone,