How to get USGS Topo Map Hi Res

New to OSM.
I have searched up and down.
I am trying to figure out if the OSM actually has the hi res USGS Topo maps in it or does it only contain objects, trails, roads and such.
I can convert the OSM for my area using mkgmap to load to basecamp, but their is no topo.
I used JOSM to import my OSM and the USGS topo showed up, but it is not in the OSM file that I save.
I am struggling if I am even trying to do the right thing here.
All I really want is a high def topo (7.5’ 12k) topo of the southern half of my state and I have spent way too many hours trying to figure it out.
Is OSM the wrong place to be looking? I am confused at why I can see exactly what I want in JOSM (USGS Topo) but I can’t get it to basecamp.
Edit: I guess I am trying to get the .img file for the USGS Topo at 12k level.

You are mixing up what is available as a background (image/bitmap) layer in JOSM, with what is actually in OSM (as data).

In principle if something is missing from OSM in your area of interest, you could potentially add it to OSM (assuming that the USGS maps are a legit source), but if that makes sense depends on your application.

If you want OSM data + contour lines, look here
You need to use phygtmap and mkgmap.

If that isn’t what you want, you might look for something here: