Columbia subject headings:
Animals--Effect of habitat modification on--Yellowstone National Park.
Habitat (Ecology)--Yellowstone National Park.
National parks and reserves--Wyoming.
Nature--Effect of human beings on--Yellowstone National Park.
Outdoor recreation--Environmental aspects--Yellowstone National Park Region.
Recreation areas--Wyoming.
Winter sports--Environmental aspects--Yellowstone National Park Region.
Yellowstone National Park.
Harvard subject headings:
Princeton subject headings:
National parks and reserves--Wyoming.
Recreation areas--Wyoming.
Yellowstone National Park.