The Sierra Nevada region of California is its alpine region, covering a large portion of the state's inland territory. Rugged mountains and awe-inspiring canyons in the area's national parks and forests are truly part of the United States' national wilderness treasures.
It's a region of grandiose sizes; Mount Whitney, the highest peak in the contiguous U.S., is here, as well as the giant sequoias, the largest living things on earth. The human population, however, is relatively small. Most of the towns and cities in the Sierra Nevada region are ski resort towns, or gateways to the area's parks.
When hiking or backpacking where you will be far from help, check the weather first. The first snows of Winter may come earlier than you expect.
In summer during the North American Monsoon, thunderstorms often build up near the crest of the Sierra Nevada, particularly during late afternoon. It is unwise to be in a high, treeless place during a thunderstorm. If hiking far in summer, it's a good idea to carry a light rain jacket just in case a thunderstorm pops up out of nowhere.