Extend your journey of body, mind, and spirit with this list of recommended books. There are kid-friendly titles along with great reads for high school students and adults.

In a single century, the salmon population of Washington State's Elwha River shrunk by more than 99 percent. What caused this dramatic decline, and what can be done to turn it around?

From a humble start 25 years ago tossing seed-filled water balloons into abandoned city lots, the Green Guerillas have grown into an organization that has created and maintains 1,000 urban gardens.

In the world's largest tropical lake, Nile perch have eaten their way through all but one of their prey species, bringing the ecosystem close to death. But don't blame the perch—humans are at fault.

There are more than 260 distinct ecosystems in the United States. Yet only a little over half of them are in protected wilderness areas. What does it take to obtain "wilderness status"?

In the mid-1970s, only 100 of these parrots were left in the wild. Learn how an international effort more than tripled the St. Lucia parrot population in 20 years.

Humans have harmlessly harvested coral reefs for thousands—or even hundreds of thousands—of years. So why has our behavior in recent years suddenly put reefs at risk?

Because they feed on everything from monkeys and pacas to armadillos and alligators, jaguars play a key role in the rain forest ecosystem. Learn how protecting them safeguards the jungles of Belize.

Which regions of the world have seen the greatest rates of mammal extinction? Surprisingly, it's not the Amazon rain forest nor the clear-cut forests of the U.S. or Africa's Serengeti plain.

If you want an idea of the conditions on Mars, journey to Antarctica. Take a close look at the work of an astrobiologist studying Antarctica's valleys, the "most Mars-like places on Earth."