This collection consists of ten diaries belonging to J.S. Hyatt. They provide insight into his day-to-day life and his work as a civil engineer, with the majority of the diaries documenting various appointments and meetings.

The Ruth Hendrickson Wood Diaries record her day-to-day life. They contain writing about daily activities, oftentimes noting the weather. The diaries include musings on social engagements and other events. They have also been used to keep track of scheduled appointments and travel dates.