1814-1910
- One of Yosemite's earliest explorers, its first public guardian, and one of its most revered hosts, tour guides, and protectors for most of his life. He was a charter member of the Sierra Club.
- Galen Clark, with Milton Mann, was one of the earliest white settlers to explore the Mariposa Grove of Giant Sequoias in 1857.
- In 1866 Clark was appointed to be the first Guardian of the new Yosemite Grant, and he served in this role for twenty-one years.
- John Muir met Galen Clark on his first visit to Yosemite, and later called him "the best mountaineer I ever met, and one or the kindest and most amiable of all my mountain friends."
- Clark wrote several books, including Indians of the Yosemite (1904), The Big Trees of California, Their History and Characteristics (1907), and The Yosemite Valley (1910). Exhibiting modern ecological knowledge informed by traditional Indigenous knowledge, Clark believed that the problem with Yosemite National Park was that it needed Native people to come back and burn the land and tend the oak trees so that vegetation would not overtake the Tuolumne Valley.
- John Muir wrote a Tribute to Galen Clark as chapter 15 in his book, The Yosemite.
- For more information, see Galen Clark: Yosemite Guardian by Shirley Sargent.