Outdoor Explorers

Photo above: After spending several days in the deep bottom, a skilled hiker pauses to hydrate after ascending the majestic Grand Canyon in Arizona, USA. Scientists believe the steep-sided gorge--277 miles long and over a mile deep--was carved 6 million years ago by the magnificent Colorado River.

Although the Grand Canyon has lttle vegetation, except for parts of the rim, it is a spectacular and complex natural habitat for over 1,500 plants, 355 birds, 47 reptiles, 9 amphibians, 17 fish species, and 89 mammals, including the thirsty guy in the photo.