The Donald Olsen Collection spans the years 1941-1998 (Bulk dates 1952-1989) and includes files created by Olsen while working with Vernon DeMars and Joseph Esherick on Wurster Hall. The collection is organized into six series: Personal Papers, Professional Papers, Faculty Papers, Office Records, Project Records, and Major projects. The collection is extensive and contains a wide range of materials documenting Olsen's long career as an architect and professor at the University of California, Berkeley. His career focused heavily on designing residences, of which many are well documented in this collection.

The Personal Papers contains biographical material, personal correspondence, financial records, student work, and certificates/degrees. The Professional Papers includes correspondence with other architects, awards, and a mixture of records that include correspondence and presentation notes related to professional organizations, committee work, juries, as well as research and reference files. The Faculty Papers contain material related to Olsen's professorship at the College of Environmental Design at UC Berkeley. Primarily, this series contains official correspondence with other members of the UC Berkeley Architecture faculty, committee work documentation, and course materials such as syllabi, lecture notes, and slides from classes he taught.

The Office Records document administrative operations, public relations efforts, financial transactions, and correspondence. Clippings from newspapers and tear sheets from magazines in which Olsen’s projects were featured, and some photographs are included. The majority of the Projects Records series documents Olsen's projects spanning the years 1942-1994, and documents his work through drawings, photographs and slides, administrative files, and one model. The majority of projects are residential in nature. Major Projects within this series include UC Berkeley, Le Conte Hall (1964-1968) and UC Berkeley, Wurster Hall (1960-1964), where a significant number of plans and drawings are retained. Additionally, a large amount of material includes the School of Arts and Sciences (1970-1974) and Richmond Sanitary Service Company (1973-1974).