Born in Scotland, Keith immigrated with his family to New York in 1850. Keith found his way to San Francisco in the early 1860s after traveling first to London. In 1868, he exhibited his first oil paintings and soon after accepted a contract with the Oregon Navigation & Railroad Company to produce scenic views of their lands in Oregon.
Keith traveled to Düsseldorf and then explored Italy and Switzerland before going to Paris. In 1871, Keith showed at National Academy of Design. He then returned to California and met John Muir; the two men, both immigrants, both lovers of California, would work together to found the Sierra Club.
Keith initially favored panoramic views of the Sierras and California’s Coastal Range. As time went on, however, his work evolved toward a more subjective style, influenced perhaps by painters of the Barbizon School. Later he became friends with George Inness and adopted a Tonalist style. Keith’s works in this style were popular and he continued to experiment with new methods.