Frommer's National Parks of the American West (7th ed.)

* With full coverage of Western national parks: Arches, Badlands, Big Bend, Black Canyon of the Gunnison, the Black Hills (including Mount Rushmore), Bryce Canyon, Canyonlands, Capitol Reef, Carlsbad Caverns, Channel Islands, Crater Lake, Death Valley, Devils Tower, Glacier National/Waterton Lakes, the Grand Canyon, Grand Teton, Great Basin, Great Sand Dunes, Guadalupe Mountains, Joshua Tree, Lassen Volcanic Park, Mesa Verde and the Four Corners, Mount Rainier, North Cascades, Olympic, Petrified Forest, Point Reyes, Redwood, Rocky Mountain, Saguaro, Sequoia and Kings Canyon, Theodore Roosevelt, Yellowstone, Yosemite and Zion. * According to the National Park Service, as of June 2009, 127.7 million visits were made to national parks in the first six months of the year, an increase of about 4.5 million over the same period in 2008.* More than 900,000 people visited Yellowstone National Park in July, 2009, an all-time record for monthly visits and a jump of 94,000 visits over 2008.

The First Family visited Yellowstone in August, 2009.