States: Virginia: Dickenson
Twin Branches is an area on the North side of John Flannagan Reservoir. It is just "downstream" from the junction of the Pound River and the Cranesnest River. A lot of the Twin Branches area is under water now. You can tell approximately where the Upper Twin Branch and the Lower Twin Branch flowed into the Pound River by a small vertical-walled rock island sticking up out of the waters of Flannagan Reservoir, but the only way to get to the island is by boat.
I'll try to send you a Topographic Map by e-mail.
If I can be of more help, post again.