No genealogist wants to hear “the courthouse burned and all the records were destroyed.” The reality is that sometimes that statement is only partially true. Other times there are partial workarounds to those times when a courthouse and its records were really destroyed.
The first thing to do is to determine what actually was destroyed. This may mean reaching out to others besides the local records offices. In some locations research guides to the area in question may indicate what materials really were destroyed and what ones are still extant. Local libraries, genealogical/historical societies are a good place to start asking about what records are available.
Individuals familiar with research in the area can be another great resource. These people may not live in the area and may not be members of local societies. Ask around if there is anyone who has done extensive research on families in the area and see if it is possible to reach out to this person.
State or regional archives may have materials related to the area in question. FamilySearch may have copies of some materials as well.
In some cases, after a facility’s records were destroyed, local individuals may have been told to bring in their original deeds or other items that had been recorded to have them recorded. Others may have documented land ownership through affidavits and depositions.
Finally, state or federal records may provide some information on your ancestors as well as newspapers, cemeteries, church records, etc.