Horsfall enjoyed painting wildlife, and contributed to a number of field guides, scientific publications, and conservationist works. He was a member of the
American Ornithologists' Union, the
Cooper Ornithological Club, the Northwest Bird and Mammal Society, the
American Society of Mammalogists, and the
American Museum of Natural History. Horsfall's paintings were first exhibited in Chicago in 1886, and later at the
Chicago World's Fair in 1893. At the time of his death in 1948, there were permanent exhibitions of his work at the
Peabody Museum of Natural History at
Yale University, the Kent Scientific Museum in Grand Rapids, Michigan, and the Zoological Museum at the
University of Minnesota. Two portraits he painted were also hung in Guyot Hall at
Princeton University. In 2023, the
Oregon Historical Society showcased 55 of Horsfall's watercolor bird paintings in the exhibition
Birds of the Pacific Coast: The Illustrations of R. Bruce Horsfall. ==Publications==