The collection consists of records pertaining to G. L. Henderson and his family including his son and daughter-in-law, Walter J. and Eva Fitzgerald, as well as daughters and sons-in-law, Jennie and George Ash, Mary and Henry Klamer, and Barbara and Alexander Lyall. The records consist of biographical and genealogical materials, business records, correspondence, writings, and ephemera. The biographical and genealogical materials detail the history and familial relationships of the Henderson and Fitzgerald families. Business records include records documenting the creation, construction, and management of the Cottage Hotel and Cottage Hotel Association as well as its sale to the Yellowstone Park Association (YPA) and Henderson's subsequent employment by the YPA as a lobbyist. There are also records of Henderson's employment as assistant superintendent of the Park, including the earliest known register of park visitors, weather logs, and a few copies of memoranda and correspondence. Other family members were employed at various times as postmaster and post office records include logs of certified mail and deliveries. Correspondence covers similar topics of business as well as materials from the military administrators of the Park and the Northern Pacific Railroad. There are also a few pieces of family correspondence. All of the writings were authored by G. L. Henderson and include poems, essays, and news articles. The main focus of these writings is the attractions of the Park, including the thermal features and amenities for visitors. Ephemera were likely collected by several family members, although G. L. is evident as both collector and subject. These items range from advertising cards, blank letterhead, and envelopes to published reports, maps, and news clippings compiled into scrapbooks. Broad themes documented by the collection include the early civilian administration of the Park, the transition to military oversight, and the administrative and poaching problems that led to the change. Also documented are the earliest activities to cater to tourists including G. L.'s role in developing Park interpretation, marketing and boosterism, and the beginnings of commercial services via concessioners. The role of national politics is evident throughout the collection, particularly the ongoing conflict of conservation versus economic development. In addition to topics concerning Yellowstone National Park, there are a few items pertaining to the Henderson family's life prior to moving west. The records provide documentation of a literary society in Levy, Minnesota, as well as an attempt at communal living organized as the Clemont Home and Produce Company in Postville, Iowa.

For a detailed history of G. L. Henderson and his family see Whittlesey, Lee. Storytelling in Yellowstone: Horse and Buggy Tour Guides (2007) and Goss, Robert V. "Yellowstone's First General Store: A Legacy of Jennie Henderson and Her Family, " Yellowstone Science 13.2 (Spring 2005): 16-28. 1882-Henderson appointed assistant superintendent of Yellowstone National Park. 1882 May-Henderson and daughters, Helen L. "Nellie", Barbara G. "Lillie", Jennie H., and Mary Rosetta, arrive in Yellowstone. 1882 July-Barbara appointed post mistress of Yellowstone. 1883-Barbara and Jennie sell tourist curios at the Post Office. 1884-Jennie appointed post mistress. 1885-Henderson publishes Yellowstone Park Manual and Guide. 1885 June-Henderson loses position as assistant superintendent. 1885-Henderson family constructs Cottage Hotel. Walter and Helen named as proprietors. 1885 December-Cottage Hotel opens. 1886-Jennie loses post mistress appointment to Marion Baronett. 1886-Jennie elopes with John Dewing. 1887 Nov.-Helen marries Charles Stuart. 1888-Jennie appointed post mistress, sells curios under name of Post Office Store. 1888-Walter marries Eva Fitzgerald. 1888-Henderson hires daughter Helen as park interpreter (1st female park interpreter). 1889-Mary named assistant postmaster. 1889 May-Henderson sells Cottage Hotel to Yellowstone Park Association; hired by YPA as congressional lobbyist. Continues as park interpreter. 1889-Walter and Eva operate Firehole Hotel, Helen and Charles operate Cottage Hotel for YPA. 1891-Henderson establishes home in Chula Vista, California, and begins spending winters there. 1892-Mary marries Henry Klamer. 1893-Jennie divorces Dewing. 1893 June-Jennie marries George Ash. 1895-Jennie awarded 10 year lease to build a store, post office, and residence at Mammoth. 1897-Henry Klamer takes over store at Old Faithful, Henderson works there for the summer. 1898-Barbara marries Alexander Lyall. 1899-Henderson works at the Wonderland Post Office. 1900-Jennie takes over as postmaster from George. 1900 June-George Ash dies in Salt Lake City from extended illness. 1902-store renamed Yellowstone Park Tourist Supplies. 1905 August-Jennie's lease renewed for 10 years. 1905 Nov. 14-Henderson dies in Chula Vista, California. 1906 Jan.-Jennie resigns as postmistress, recommends Alexander Lyall. 1906 Feb.-Lyall appointed postmaster, joins store operation under J. H. Ash & Co. 1908-Jennie retires to California, store taken over by Lyall and Walter (Lyall & Henderson). 1913-George Whittaker takes over from Lyall & Henderson. 1914 August-Henry Klamer passes away. 1915 June-Charles Hamilton purchases Klamer's Store at Old Faithful. 1929-Charles Stuart passes away. 1936-Helen Henderson Stuart passes away. 1941-Barbara Henderson Lyall passes away. 1947-Jennie Henderson Ash passes away. 1948-Mary Henderson Klamer passes away.