英文關鍵字
america
american
animal
basin
bison
buffalo
castle
cold
erupt
erupting
formation
geyser
geysers
herd
hot
landscape
limestone
national
park
pool
pools
rock
spring
springs
states
steam
steaming
united
upper
usa
vent
vents
water
wild
wildlife
winter
wintertime
wyoming
yellowstone