Viewing TOPO US 24K Maps in BaseCamp

How do I transfer my TOPO US 24K maps to BC?

Here is what I want to do. I have TOPO US 24K maps for Northeast, Southeast and Northcentral on my Montana 600. I can view these maps in BC when my gps is plugged into my laptop. If I unplug the gps the map data goes away.

Is there a way to copy these maps into BC for permanent access without the gps being plugged in??