Sunset on Mount Diablo by William Keith.

Mount Diablo has inspired many artists and writers. Early work centered on exploration, surveying and was related to the rise and popularization of tourism in the Pacific west. Themes were suggested and heightened by early tourism promoters, the beginnings of the area's preservation and the rise of the environmental movement.

William Keith (November 18, 1838 ??April 13, 1911) was a Scottish-American painter famous for his California landscapes. He is associated with Tonalism and the American Barbizon school. Tonalism was an artistic style that emerged in the 1880s when American artists began to paint landscape forms with an overall tone of colored atmosphere or mist. Between 1880 and 1915, dark, neutral hues such as gray, brown or blue, often dominated compositions by artists associated with the style. During the late 1890s, American art critics began to use the term 'tonal' to describe these works.