If the property was inherited through an estate then you may be able to find the FMV when you inherited the property. If that is not possible then records with the county assessors may be able to provide you with that information if their records go back that far. You may have a local title company research the sales records for the property, or local real estate records may provide the information. Failing to get actual records on the property use whatever reliable resources are available to calculate a reasonable estimation of the FMV in 1989.
