Sky Pond at Rocky Mountain National Park.

(Photo: Steven Bratman)
Some of this country’s most loved national parks were only created after lots of controversy.

That’s true of Rocky Mountain National Park, Yosemite, and Yellowstone.

Bob Keiter writes about this in his new book, "To Conserve Unimpaired: The Evolution of the National Park Idea."

In the book, Keiter also explores the growing tension in parks between conservation and throngs of tourists.

Keiter teaches environmental law at the University of Utah. He spoke with CPR’s Lesley McClurg.