I just downloaded the Map Pack for RV1 and now the folder is just chillin on my desktop. I run it through steam and when I direct myself to the vegas1 folder I have the following folder options to store the Map Packs:

BINARIES
DETECTION
DIRECTX
ENGINE
KELLERGAME
REGISTER

Thanks in advance.

I haven't used steam in a long time, but if remember correctly, it seems that steam auto updates it's games.