The county in southwestern Virginia which went Democrat in 2013 and 2014 is Montgomery County, which has Virginia Tech. It went narrowly for Obama in 2008 and for Bush over Kerry in 2004. I don’t know the explanation for Alleghany County, the other western county (on the WV line) that went Democrat in 2014...it has a fairly small population.
I know about Montgomery, which unfortunately is trending rodent because of the students. Alleghany is rather schizo in its habits. Mark Warner seems to be “popular” there for some unknown reason. He got a whopping 74% of the vote in 2008 over ex-Gov. Gilmore and still managed to hang onto 53% apparently. Conversely, George Allen carried it 52-48% over Kaine in 2012 (though lost it back in 2006 52-47% to Webb).