Henry J. Biddle (1862-1928) was an engineer and an amateur botanist. The collection consists of diaries, trip logs, account books, correspondence, manuscripts, sketch and survey maps, and photograph prints and albums.
Walter S. Bowman (1865-1938) was a professional photographer who worked in Pendleton, Oregon, from the late 1880s to the mid 1930s. Bowman's photographs document daily life in Eastern Oregon, including special events such as the Pendleton Round-Up. The collection consists of almost 800 negatives and prints representative of the span of the photographer's work, but his noted images of tribal people were largely destroyed after his death.