Sullivan's papers, which were given to Holt Atherton in 1965 by Helen Morgan, consist of four series of materials. Series 1 is Sullivan's Smith correspondence. Series 2 consists of Sullivan's notes on Smith. Series 3 is made up of several copies of an 1831 transcript of Smith's journal. Series 4 consists of four versions of draft chapters of Sullivan's book Jedediah Smith: Trader & Trailbreaker and an early version of Sullivan's edited form of the Smith journals published as The Travels of Jedediah Smith.

Having contracted tuberculosis, New Jersey newspaperman, essayist and friend of H.L. Mencken, Maurice Sullivan (1893-1935), left his home for California in the early 1920s. He settled at Redlands, where he worked first as a writer and ultimately an editor of the San Bernardino Daily Sun. Sullivan devoted much of the rest of his short life to researching and writing the books on Jedediah Smith upon which his reputation rests. Sullivan initiated correspondence with various members of the Smith family and gained access to primary sources which were not then in public collections. His most important discovery was an 1831 transcription of several of Jedediah Smith's journals that had been preserved by the family since the explorer's death.

Collection is open for research.