Over the past century, the United States has led the world in dam construction. There are at least 90,000 dams over six-feet tall in this country and over 2 million shorter than six feet. More than a quarter have passed their 50-year average life expectancy; by 2020, that figure will reach 85 percent. On average, we have constructed one dam over 6 feet tall every day since the signing of the Declaration of Independence.

On this episode of America's National Parks, the removal of the dams on the Elwha River in Olympic National Park. And if you think it just takes a little dynamite, it doesn't. 

Show notes and music credits at nationalparkpodcast.com/elwha.