The recovery history is stored in a file named db2rhist.asc dot something under the database path
./NODE0000/SQL00001/db2rhist.asc
./NODE0000/SQL00001/db2rhist.bak
There is a backup file also, in case , one gets corrupt ..
As an additional bit of info, whenever a backup is done, the recovery history information is also backed up and it is possible to restore only the recovery history file from the backup image (of course, the history will not be current, but still you have the option)
HTH
Sathyaram