The East Bay Regional Park District commissioned a study to determine the historical significance and conditions of existing buildings at two sites on the Black Diamond Regional Preserve, the Arata Ranch, which dates from the early 1900s, and Sidney Flat, the current location of staff offices and a visitor’s center. Knapp prepared a Historic Resource Study cataloguing the history and conditions of over 50 buildings and structures and assessed their historic significance working closely with District naturalist Traci Parent, who provided valuable history and feedback. This was followed by a Reuse Feasibility Study to assess the Arata Ranch and five of its buildings for reuse, including the Caretaker’s House, Dairy and Horse Barns, Main House, and Milk Separator Building. The Reuse Study included architectural and structural surveys coordinated with DCI Engineers and recommendations with conceptual cost estimates by Hattin Construction Management. Archeo-Tec performed an archaeological survey and compiled a third report for the properties. We worked closely with District staff to evaluate their needs and provide relevant information for rehabilitation of the buildings and site to inform the District’s long range planning for the preserve. We have since prepared construction documents and coordinated structural work for our current project to stabilize, reroof and mothball the Dairy Barn until future rehabilitation and reuse.