Santa Rosa's second library building was dedicated in March 1904 with a Carnegie grant,[6] although the 1906 earthquake damaged it badly.

During this period, new library buildings opened in Petaluma (1976), Healdsburg (1988) and Guerneville (1988); additional library branches opened in Santa Rosa's Rincon Valley (1994) and Windsor (1996) and Rohnert Park (2003).

In November 2015, a temporary storefront library was established in the Roseland district of southwest Santa Rosa to serve Roseland's predominantly Latino community; a permanent facility is planned for the site as part of a redevelopment project.

[9] The library is funded predominantly by a parcel tax levied on properties within its jurisdiction.

The bigger branches are located in the largest communities of Santa Rosa (with three locations), Petaluma and Rohnert Park, with small branches and storefront libraries (or rural stations) serving the remainder of the County.