Historian Douglas Brinkley spoke with CBS Early Show anchor Harry Smith about the state of our national parks his new book The Wilderness Warrior: Theodore Roosevelt and the Crusade for America, an instant New York Times best-seller.

Dr. Douglas Brinkley has been hailed by the Chicago Tribune as “America’s new past master,” and the late Stephen E. Ambrose called him “the best of the new generation of American historians.” He is the author of a number of award-winning and best-selling books, including The Great Deluge, Tour of Duty, The Boys of Pointe du Hoc, Parish Priest, and, he edited the number one New York Times best-seller The Reagan Diaries, the personal diaries kept by Ronald Reagan during his time in the White House.