@Yosemite National Park is located in the @Sierra @Nevada Mountains of central @California. It is so spectacular and awe-inspiring that @John @Muir, the @Sierra Club founder, called it "a landscape ... that after all my wanderings still appears as the most beautiful I have ever beheld."

Over millions of years, earthquakes, glaciers, and other forces of nature have left their mark. They are visible in the granite cliffs, thundering waterfalls, steep mountains, and deep alpine lakes. Each one invites visitors to explore, climb, photograph, and experience their grandeur.

Yosemite's geological history has changed over the last 500 million years. The entire area was originally part of the ocean floor. Only later did it become gentle, rolling hills, and then the steep Sierra Nevada mountain range, filled with deep river canyons.

Three million years ago, the ice age brought glaciers. These scraped and carved the valleys and canyons with such force that the remaining granite still shows the direction of their movement. Those same glaciers created massive rock formations that present some of the most difficult and popular climbing challenges in the world for today's enthusiastic rock climbers.

When the last glacier finally melted 10,000 years ago, rock debris dammed the valley and created Lake Yosemite, while tributary creeks plummeted off sheer cliffs and gave birth to the park's famed waterfalls. Sediment continued to fill the lake until it eventually formed the present valley floor.

Yosemite's geological evolution continues today as Mirror Lake slowly fills with sediment in much the same way as Lake Yosemite did.