If you're using an OverDrive account:
Bookmarks are automatically saved to your account as long as the "Automatic syncing" setting is turned on. Simply download the title again, and your bookmarks will show up when you open that title in the app.
If automatic syncing is turned off, you can manually sync bookmarks by dragging down on your bookshelf.
If you're not using an OverDrive account:
Your bookmarks will be saved in the OverDrive app as long as:
- The title hasn't been deleted from your history.
- The OverDrive app hasn't been uninstalled.
- Android only: The app cache hasn't been cleared in your device settings.
Once any of these conditions occur, you will lose any data associated with that title.