Land ownership is a matter of public record. I would start a database or spreadsheet and start looking at land ownership records, try to figure out who else is

Land ownership is a matter of public record. I would start a database or spreadsheet and start looking at land ownership records, try to figure out who else is (likely to be) in the same boat and try to contact them individually. https://california.staterecords.org/propertyrecords#:~:text=California%20citizens%20and%20residents%20can%20obtain%20property%20records,at%20the%20county%20clerk%E2%80%99s%20office%20in%20some%20instances https://california.staterecords.org/propertyrecords#:~:text=....