Sonoma Valley Historical Society was formed in 1937 as non-profit. Dedicated to collection and preservation of historic heritage of the "Valley of the Moon." The historical society supports the Depot Park Museum which is open five days a week, and is free to the public.
The SVHS has accumulated over 40,000 photographs, slides and negatives reflecting the history of the museum. Depot Park Museum is also home of the "Bear Flaggers," the men who came to Sonoma and raised the Bear Flag over Sonoma in 1846. Mexico eventually gave up claim to High California, and the state of California was approved in 1850, when it joined the Union.