Do you know this boulder?

3.10.09OrganMountains.WhiteSandsNM 293

This large boulder is along the road to the Aguirre Springs Campground at Organ Mountains-Desert Peaks National Monument.   Anyone know its geology?  I wonder if it fell off the cliffs in the background and rolled across the desert or if when they made the road they simply moved it out of the way.   Let’s talk Chihuahuan Desert geology.   Please forward this blog to any of your geologist friends out there.