This is one of three deck girder bridges over Martins Fork in Harlan County KY between Chevrolet and Cawood.  They were constructed in 1928 by the   Bethlehem Steel Company in Bethlehem PA.  This line is active CSX, but I suspect the line was put in by the L&N.  There’s a spur line, now dead, just north of here at Lenarue that parallels (sort of) Hwy 990 up to the Mary Helen mines.
This particular bridge is just off Hwy 3001 over Martins Fork.  It’s about 280′ long.