The John Upton Clowdsley collection contains personal papers, office and project records. Personal papers consist of Clowdsley's student work from UC Berkeley. Office records include cost estimate cards for approximately 160 of Clowdsley's projects and photographs of completed projects. Project records represent more than 65 of Clowdsley's projects and consist primarily of residences in Stockton and San Joaquin County and drawings for the Stockton City Hall.