http://wvcsb.org/churches/info/simpson_ ... ist_church
The oldest and largest ABC-USA congregation in West Virginia has affiliated with the West Virginia Convention of Southern Baptists. I haven't seen a news article to that effect, but knew it was in the works a couple of years ago. I'm guessing they're dually affiliated since they are still listed with the WVBC, which is the ABC-USA affiliated convention. I have family members there, my paternal grandfather's brothers were both members and they both still have children and grandchildren who are members there. My great grandparents were both members there as well. The church was organized in 1770 and according to their in-house historians is the oldest Baptist church west of the Alleghenys. There's a church in Elizabethtown, Kentucky, Severns Valley Baptist, which lays claim to the same title but its records show that it was organized in 1783.
Apparently West Virginia Southern Baptists are not bothered by dually affiliated ABC congregations since there are several of them. Simpson Creek has always seemed much more like an SBC congregation to me, though in West Virginia, many of the ABC-USA churches are like that, at least, the ones I've attended are. The pastor at Simpson Creek is a Southwestern grad, and I think one of their other staff members went to Southern.