The League’s Sonoma/Valley of the Moon Historic Survey, begun in 1977 and updated several times since, covers nearly all local structures 50 years old and older. It is now accessible online through this website for easy reference.
The League’s Archive, with its collection of maps, documents, news clippings and photographs, is maintained in Maysonnave House.
The League’s Advocacy Program protects historic Sonoma structures from demolition or significant change through neglect or redevelopment.
The League’s Awards Programs through which it recognizes leaders in local historic preservation efforts in both public and private activities.
The League’s Sonoma Walking Tour Brochure highlighting historic commercial and private properties on and around the Plaza for residents and visitors to find and appreciate our preserved heritage.
The League’s Historic Facade Easement Program by which the League protects the exterior of iconic buildings around the Plaza through deeded rights under California law.

Promotes surveys and studies that support historic preservation in Sonoma and surrounding valley.
Encourages responsible design for renovations and new construction where proposed in historically significant cultural landscapes.
Supports individuals and organizations that are actively engaged in historic preservation, especially for educational purposes.
Presents the Margaret F. Eliassen Founder's Award for Leadership in Historic Preservation to worthy recipients as well as other awards recognizing historic preservation achievements.