yellowstone's upper geyser basin, home to old faithful and more

geyser wyoming steam nature outdoors horizontal color hot spring geology usa yellowstone national park erupting upper basin volcano thermal landscape old faithful western eruption castle famous travel destinations people geothermal vacation unesco world heritage site beauty caldera exploding turquoise abstract active america water place heat temperature scenery yellowstone#39aph39#s home 150 geysers single square mile making dense concentration planet it#39aph39#s morning glory pool grand