A new book is highlighting some of the top-secret locations in America that could serve as a de facto White House in the event of a nuclear strike. A bunker built into a hollowed out mountain in Colorado is just one of the covert shelters where 7,000 Americans will go to in the event of nuclear annihilation, according to Garrett Graff, the author of 'Raven Rock: The U.S. Government's Secret Plan to Save Itself While the Rest of Us Die.'