The papers of Ullman (Princeton Class of 1929) contain manuscripts of most of his major works, many shorter works, correspondence, and subject files. Included are nine nonfiction works, such as High Conquest (Phila.: J.B. Lippincott, 1941), Americans On Everest, and Mad Shelley (Princeton: Princeton University Press, 1930); ten novels, including The Day on Fire (Cleveland: World Publishing Co., 1958), based on the life of Rimbaud, The Sands of Karakorum (Phila.: J. B. Lippincott, 1953), and The White Tower (Phila.: J. B. Lippincott, 1945); twelve plays; and numerous articles, short stories, and poems. In addition, there are diaries (1920-1971), financial papers, documents, photographs, magazines containing his works, and papers of other persons, where plays produced by Ullman, but written by Lynn Root, Irving Ramsdell, and others, have been filed.

Ullman's correspondence contains letters of fellow adventurers, family, and friends, such as Norman Dyhrenfurth, Temple Fielding, Robert Kaufman, J. Monroe Thorington, and Alexander F. Ullman (his father, who lived in New York City), as well as fan mail from 1935 to 1971. The subject files reflect his interests in mountaineering, Robert Kaufman, world travel, and literature, and include notes, letters, and printed matter pertaining to the American Mt. Everest expedition (1963), of which Ullman was a member, the American Field Service, Broadway shows of the 1930s, and travel brochures and itineraries to the South Pacific, Africa, South America, and other global points.