Yellowstone National Park turns 140 years old this month.  Yellowstone was the first area in the world to be designated a national park.

	Frommer's Yellowstone & Grand Teton National Parks / by Eric Peterson.
	Decade of the wolf : returning the wild to Yellowstone / Douglas W. Smith & Gary Ferguson.
	Knowing Yellowstone : science in America's first national park / Jerry Johnson, editor.
	The national parks [DVD-videorecording] : America's best idea / a production of Florentine Films and WETA Television ; written by Dayton Duncan ; produced by Dayton Duncan and Ken Burns. Traces the birth of the national park idea in the mid-1800s and follows its evolution for nearly 150 years.
	Welcome to Yellowstone National Park / by Teri Temple and Bob Temple. The first park -- Mammoth country -- Roosevelt country -- Canyon country -- Mud Volcano Trail -- Lake country -- Geyser country -- Fast facts.