Finding marriage records can be difficult even when you know the date of the marriage.
Thankfully, those searching for marriage records in California have a wonderful resource to help them in the article, “How to Find California Marriage Records” on the FamilySearch Wiki.
The wiki article walks through the research process step-by-step covering a range of dates starting with 1850 through 1952 and thereafter.
The research for different periods of time varies by collection and research processes. The wiki article explains the processes and provides links to online records and to the repositories that hold copies of the original documents.