William Jacob Hays spent most of his life in New York City but occasionally ventured to the Adirondack Mountains of New York, Nova Scotia, and England on search for subjects to paint. He studied art with John Ruebens Smith, an important topographer and lithographer, and exhibited at the American Art Union in 1848. His most inspirational and productive trip was a five-month journey up the Missouri River through the Great Plains, the Dakotas, and Montana to the Yellowstone River during the summer of 1860. After this expedition, Hays returned to his studio in New York City to transform his field sketches into an artistic and authentic documentation of the American West prior to the arrival of white settlers. Among his favorite subjects was the North American Bison. An accomplished naturalist and experienced observer, Hays portrayed wildlife and habitat of the American West accurately and with exquisite detail.

Hays' work is recognized in many private collections and museums, including the Denver Art Museum, the Brooklyn Art Museum, the Gilcrease Museum, the Buffalo Bill Historical Society, and the National Museum of Wildlife Art.