In many situations organizations from sports teams to corporations strive to earn the distinction of being named "Number One in the country." That's not the case, however, when it comes to a list of America's Most Endangered Rivers, and the Colorado River in Grand Canyon National Park has unfortunately earned that label on a just-released annual report.

A much publicized conference, Science for Parks, Parks for Science: The Next Century, opens today at the University of California, Berkeley. Led by the National Park Service and National Geographic Society, conference sponsors propose “to launch a Second Century of stewardship for the parks, 100 years after the historic meetings at UC Berkeley that helped launch the National Park Service.” A specialist on those meetings, Dr. Alfred Runte reports on why the story does not end there.

Across the National Park System, the National Park Service has an estimated half-a-billion-dollars of obligations owed concessionaires who run lodges, restaurants, and even some activities. It's a sum that, while agency officials say it's manageable, has seemingly stifled concessions competition in some parks and diverted tens of millions of dollars from others to reduce debts.

"Is anybody alive out there?!?" If you’ve had the good fortune to attend a Bruce Springsteen and The E Street Band concert, you know the feeling when you shout out your answer. Want to experience that for two to three weeks every day on the water? Join in on a Colorado River float trip through the Grand Canyon.