Bears have become a huge problem in Yosemite. Follow all rules in the park. Do not leave food overnight in cars. There are places to put it when parking overnight, call the information line. When backpacking you must carry your food in a bear bag that can be obtained from the visitor centers.
Reservations are hard to get for backcountry travel, call early.
At Sunset Yosemite Valley Yosemite Valley is the heart of Yosemite National Park. The Valley is set deep in a canyon flanked by high cliffs. El Capitan, Half Dome, Bridal Veil Falls and Yosemite Falls are all viewable from the valley floor. There are many backcountry trail heads here suitable for week long trips or day hikes. South of Yosemite Valley South of Yosemite Valley is Badger Pass and Mariposa Grove.