I keep forgetting the name of that goddamn map as well, but yes, it's the desert-y one with main bases in each south corner and three large bridges to the middle. I don't know what it is, but mvalley is just a terrible name.
Fun Fact: The same guy who made Mvalley also developed Fistful of Frags. As such, one of the maps has (or at least used to) have the big stack in the middle of the map as well. And yeah, it's meant to be where some meteor or satellite or someshit impacted in the Empires universe, so it's important in some way shape or form.
I think a more fitting arrangement of letters would be "expacting", although it's definitely not a /real/ word (yet).