Two things were fundamentally important to Ernest Haycox when he wrote about the West. The first was familiarity with the real-life areas he used as settings for his stories. He would visit a place, absorb the details of the topography and ambience, and translate this information into his story. The second was historical accuracy. In the 1920s, Haycox published a story about the Revolutionary War and included descriptions of the soldiers' uniforms. When he received a letter from a reader, he was appalled to find that his description was not accurate. At this early point in his career, Haycox began purchasing books on the West, developing his own personal research library. Over the years that collection grew to over 2,000 books and periodicals, many of which are rare or scarce. Among the gems are the 1880 photographic Panorama of Portland, taken by Albert Wulzen, Joseph Gaston's Portland: Its History and Builders (1911); Clinton Snowden's History of Washington (1909); Theodore Winthrop's The Canoe and the Saddle (1913); Andy Adams' The Log of a Cowboy: The Narrative of the Old Trail Days (1931); Frances Fuller Victor's The River of the West (1870); and Thomas L. McKenney's multi-volume History of the Indian Tribes of North America (1870).

In 1960 Jill Haycox, the widow of Ernest, offered the collection as a gift to the University Library, and arrangements to donate the collection of books and personal papers, which is formally called the "Ernest Haycox Memorial Library." The collection is fully cataloged and accessible to scholars. As a part of the holdings in the Special Collections and University Archives, the collection can be used in the Reading Room.