The Library's four Special Collections locations house over 200 archival collections created by local County and municipal government agencies, and by the Library itself. The collections are primarily documents, but also include many other types of materials, ranging from photographs to video recordings. Though the vast majority of these collections have not been digitized, those collections with digitized items (including collections of born-digital items) are noted in the collection guides list as well as on the Digitized Archival Collections page.
A small (but growing) number of collection guides (finding aids) can be viewed through this site; the most comprehensive set of guides can be found at the Online Archive of California
The History and Genealogy Library includes many of the smaller, non-governmental archival collections related to County history. These range from diaries to atlases, and from deeds of titles to wills. The History and Genealogy Library staff manage the Sonoma County Library Archives.
The Wine Library, dedicated in 1989, is one of the most comprehensive collections of wine information in the world. Archival collections include wine labels, photographs, rare wine books, and maps. The library oversees the IWRDB -- The International Wine Research Database, an index to wine information for the global wine research community. The Library also serves as a historical archive of the North Coast wine industry.
Located in the Petaluma Regional Library, the Petaluma History Room (PHR) houses a variety of collections relevant to Petaluma and the surrounding area. These include a large collection of legal documents related to Petaluma attorneys and cases, historical photographs, social club records, and Petaluma Adobe materials.
The Archives contain over 5,000 cubic feet of historic, archival and rare items, including paper records, photographs, maps, oversized drawings and bound volumes, encompassing both the governmental records of the County of Sonoma as well as additional local archival collections. The materials date from the 1840s to the 2010s, with more recent items being accessioned from the County based on archival designation. Items include court, tax and naturalization records; deeds, mortgages, wills and probate records; property assessments; voter registrations; Superior Court minutes; County Board of Supervisors minutes and oaths of office; road petitions, articles of incorporation and business licenses; school and library registers; maps, architectural drawings and land surveys; and original photographs and aerial negatives.
Although the collection as a whole has never been comprehensively inventoried, the Library estimates that at least 95% of the County of Sonoma governmental records are represented in brief bibliographic records in the Library’s catalog (with partially complete item records), and in collection records on the Online Archives of California (OAC). Approximately 70-80% of other materials are also represented with partially complete records.