Whitewater rafters brave the Merced River in Yosemite National Park

All plunging waterfalls, glistening lakes, fast-flowing streams, giant sequoia trees, snow-covered crags, towering cliffs and green meadows, Yosemite National Park is the United States' ultimate wilderness destination.

Although four million visitors flock here every year, escaping the crowds in this Rhode Island-sized park is merely a matter of following the black bears, deer and coyotes deep into the back country.

Occupying the western slopes of California's Sierra Nevada mountain chain, the park has 8,000 of hiking trails and 350 miles of roads to explore.

The busy Yosemite Village in Yosemite Valley makes a convenient base for further explorations of the national park. The most popular day trails strike out from here to sites such as Yosemite Falls (dropping from 2,425 feet, it is the highest waterfall in North America) and for rock-climbing on the formidable granite faces of El Captain and Half Dome.

In the summer, Yosemite is abuzz with hikers, cyclists, campers, horse riders, rock climbers and whitewater rafters, while skiing and snowshoeing in the Badger Pass Ski Area keeps the visitors coming back in the winter.

Yosemite is a three-to-four hour drive from San Francisco.