I have worked in El Paso a couple of times, the area you are talking about is pretty flat.
As for the dirt roads, they are everywhere out that way. My GPS took me on several. Many times I thought I was just driving cross country,
but there were tracks there. lol.
If it was me, I would get the deed and either call the county clerk and check ownership, or take a trip out there to check it out.
The county will probably be happy to make you a copy of the survey map of the land, showing the exact location and boundaries if you do not have one.
ETA: I see you are in Virginia, long trip to see a lot of nothing....
but if you do go, stay away from Chico's Tacos...
There is a possibility since you don't get a property bill anymore that the land was sold at auction, or there is a tax bill waiting to be paid.
As for trespassing,
if it as deserted as it looks on google earth, I doubt you will have a problem with that.
Looks like there are dirt sand roads laid out everywhere.
I am interested in the results. to me, land is land, whether people think it's worthless or not. :)