What is now called the Yosemite Valley has been home to people for thousands of years. Much of what was found originally survives, thanks to protection by both Native Americans and Americans.

The Ahwahneechee people were the first encountered by American settlers, who came sparingly at first but in droves after the discovery of gold at Sutter's Mill in 1849. Just two years after that event, the U.S. Army arrived with orders to clear the Yosemite Valley so that Americans could settle it. The Native Americans who were living there didn't take kindly to the request, and the result was the Mariposa Wars, which ended in a victory by the U.S. Army. The Mariposa Battalion, under Major Jim Savage, defeated the Ahwahneechee, led by Chief Tenaya.

A doctor traveling with Savage's Army battalion, Lafayette Bunnell, is thought to have given Yosemite its name. The name is thought to have been a derivation of a Native American word that meant "among them are killers."

Early on, settlers realized that they had something special, so no widespread settlement or devastation was visited on Yosemite. One of the first settlers to live in the Yosemite Valley with any kind of permanency was Galen Clark, who arrived in 1857 and stayed for the rest of his life, helping to build what is still today called Pioneer Village. Clark is thought to be the first American who counted the measure the trees in what is now the Wawona settlement. (Wawona is a Native American word thought to have meant "big tree.")

Clark worked tirelessly to maintain the integrity of the Yosemite Valley in the face of continued visits by explorers, travelers, and poachers. One of his most famous allies in these efforts was John Muir, himself an established botanist and outdoorsman.

In 1864, President Abraham Lincoln signed the Yosemite Grant, which gave the Valley protected status, administered by the State of California. The completion of the Transcontinental Railroad in 1869 and the addition of roads a few years later increased the number of people visiting the Yosemite Valley.

As well, entrepreneurs such as James and Elvira Hutchings, Albert and Emily Snow, and Bridget and John Degnan moved to the Valley to capitalize on the increase in the number of visitors.

State protection widened to federal protection by the U.S. Government in 1890, when Congress established Yosemite National Park. A further bill in 1906 (after a personal appeal by Muir to President Theodore Roosevelt while the two camped in the Yosemite Valley) made the U.S. Government the owner of Yosemite National Park, meaning that Yosemite was protected by the full force of federal law. The creation of the National Park Service in 1916 provided even more protection and badly needed funds to support preservation efforts. The Wilderness Act of 1964 made most of the park "highly protected," precluding development.