This guide, drawn from our complete guide to the Sierra Nevada, focuses on Yosemite, Sierra National Forest, King's Canyon, Fresno and their surroundings. Twenty-five million years ago, Yosemite Valley was a lush lowland bordered by gentle hills. Half Dome's ancestor was only 1,500 feet tall. The river was sluggish as it flowed through the valley. The land was subtropical and rain frequently drenched the valley. The river eventually carved a 20,000-foot, V-shaped canyon as it rushed toward the sea. Twelve million years later, a huge uplift of the region occurred and snow capped the highest peaks. Erosion removed the soil above the granite base and a cool climate changed the environment as hardwood and evergreen trees began to grow, and possibly the first sequoias. The region began to look like what we see today.

Today, the park occupies 1,169 square miles. The valley is about seven miles long and three-quarters of a mile wide - in other words, 1% of the park. There are 196 miles of primary roads and 800 miles of trails in the park; much of it is accessible to motorists and hikers. The main entrance to Yosemite Valley is made from the west through the dark Wawona Tunnel. After the road breaks into bright sunshine, El Capitan rears to 3,000 feet above the pine and fir-clad slopes above the valley on your left side. As you continue through the valley, Bridalveil Falls seems to emerge from the side of a mountain on your right, its mistlike water pouring 620 feet. It reaches its peak flow in May when warm temperatures dissolve the snows of winter. This remarkable guide details everything you need to know about exploring Yosemite and the surrounding parks and forests - not just the major tourist sites, but many unforgettable places few tourists ever discover. Everything you need to know about the many, many hiking and biking trails is here, as well as the beautiful rivers and lakes, the rock-climbing, the fishing, where to stay, where to eat and much more.