Re: Worldwide routable Garmin maps: URL REMOVED

Separate .img files cannot be read by your GPS. They need to be combined into a single container (confusingly also named .img). Some devices support multiple containers though.

So you need to combine the .img files into a single container .img (usually named gmapsupp.img). There are multiple ways and applications that can do this for you. Selecting the tiles on the website and request the server to make them into a map is one such way. You'll receive a download link from which you can download the gmapsupp.img.

But, since you're going to the US, you can also download large portions using Dave Hansen's work who has done the work -as described above- for you:

http://daveh.dev.openstreetmap.org/garmin/Lambertus/