I bought an Oregon 200 that came with a Canadian Topo and Road Map, i also bought US topo Map.
Everything work fine with those 2 maps... except that i love to get the road to the trails (US).

So a friend gave me a custom IMG file with the US road that need... If i upload in into my Oregon (rename gmapsupp2.img), i do get the road for both CAN and US... but i loss my Topo all together (i see some 3d topography, but no more trails)
My question: how big are the maps? Will they fit together on a (4 GByte) Micro SD-Card?

if yes: then it's easy.
- Copy them on the SD-card (the Oregon 200 has no internal memory ?)
- rename them: either gmapsupp.img and gmapsupp2.img, OR: (with firmware 3.50 ? onwards) any other name with ending .img: e.g. Topo_canada.img and Topo_US.img and US_roads.img
- select the maps you wanna see in the Oregon menu: Setup - Map - Select map
and then enable or disable the maps.
When going on the road, enable the US roads map, and disable the Topo map. On the trail, do it vice versa: disable the road map, and enable the topo map
(disabling unused maps will also speed up the display).

This works well on my Oregon 300.

if no: then use Mapsource, as described above

Chris