This Clinchfield Railroad trestle is only King Bridge Company (Cleveland OH) unit I’ve found. Made in 1907. That’s the Clinch River it’s crossing (no, it’s not..see below. It could be Cove Creek, though). This deck girder is just off Hwy. 65 south of Ft. Blackmore in Scott County VA.
Blogging the Railroad Tunnels 
That’s not the Clinch River it crosses but instead a stream going into the Clinch River.
Thank you! Appreciate the correction!