How to load Garmin U.S. Topo maps into Basecamp

Former Member
Former Member
I have installed BaseCamp on a new Mac. I still have the CDs of the Garmin MapSource U.S. Topo maps from several years ago and would like to use them with BaseCamp, but I can't find any way to load them. They are in .img format and BaseCamp seems to want .gmapi format.