SERIES I: Gatehouse Project (1995 – 1998) contains brochures, plans, drawings, invoices, contracts, correspondence, and research notes concerning the renovation of the Gatehouse area, including the design of the Pewabic plaque for the entry.

SERIES II: Historical Research (1951 – 2002) includes items Trost collected regarding the history of Cranbrook, gardeners and gardening. Materials include newspaper clippings and drawings, but are primarily composed of Trost’s research notes.

SERIES III: Area Gardens (1952 – 2005, bulk 1994 - 1996) comprises the majority of the collection. This series consists of records gathered by Trost while researching the history of the specific area gardens of Cranbrook. In January 1994, she sent CHGA chairpersons a historical research survey to complete regarding their memories of specific area gardens. Arrangement of the materials follows Trost’s original order based on a walking tour (1999) of the gardens. The survey and walking tour list are located in folder 1:18. Folder titles maintain Trost’s names for each garden. The contents of each folder vary, but generally include documentation of the development and history of each garden: drawings, lists of plants found in the specific gardens, information about the people who worked in the garden, responses of garden chairpersons to Trost’s survey questions, and clippings.

SERIES IV: Oversized Material (1998) consists of a foam display board of the Pewabic plaque for the Gatehouse Project with photos, drawings, and a brief history of the installation of the tile.