California law allows for what is called service by publication when a spouse cannot be located. This is the legal mechanism designed for exactly this situation, where the petitioner has made a genuine effort to find the respondent and been unable to.
The process works like this. The inmate files the divorce petition with the Superior Court in the county where they were last living as a couple or where they are currently incarcerated. They then ask the court for permission to serve the respondent by publication rather than direct personal service. The court requires evidence that a reasonable search has been conducted, which might include attempting to contact known relatives, checking last known addresses, and documenting those efforts.
If the court grants permission, a notice of the divorce action is published in a local newspaper for a set period, typically four weeks. If the respondent does not respond within the required timeframe after publication, the court can proceed with a default divorce and grant the dissolution without the respondent's participation.
Inmates handle their own court filings regularly in California, and the prison law library has the forms and procedural guides needed to file in propria persona, meaning without an attorney. The facility is also required to give inmates reasonable access to legal materials and assistance when pursuing legitimate court actions.
This takes time and follows procedural steps, but it is a recognized path and the courts are accustomed to handling it.