Collections Local History The library holds print and digital resources focused primarily on the communities, cultures, and unique characteristics of Sonoma County. Learn more. Genealogy The library houses an extensive collection of local, national, and international genealogy resources. Learn more. Digital Collections Sonoma County Library’s Digital Collections contain a variety of digitized historical materials, including over 45,000 photographs and postcards. Learn more. Sonoma County Archives The History & Genealogy Library collects and maintains local history archival material and manages the archives for the County of Sonoma. Learn more.