Back in 1945, Blue Diamond Coal Company, out of Knoxville TN, opened up the Leatherwood mine complex, about ten miles up Leatherwood Creek from the North Fork of the Kentucky River. At the same time, the L&N ran a spur from their main line on the north side of the river to the mines and, in order to handle the vast amount of coal coming out of Leatherwood, the railroad also built a breakdown yard a little further up the river toward Hazard, near a town called Dent (it’s gone now). At the intersection of the main line and the spur (at 37.12946, -83.08649, nearest Google Earth locator is Cornettsville KY), a complex was built to service the locomotives. It included a turntable (see it here), a pumping station to bring water up from the river to a tank used to service the steam locomotives, and various other buildings. The remains of the turntable are still visible:

To get a sense of scale, that’s my buddy standing over on the other side of the foundation (he’s dressed in white). The remnants of the pumping station and various other buildings are still there, also. This yard operation only lasted about a decade or so.
This is looking toward where Dent Yard once was:

But one thing had me puzzled. Just a short way down the river from the main trestle, I saw these:

To answer your question about the stone piers: built by w m ritter logging company. Their band mill was located about 3/4 mile up Leatherwood Creek. They operated “Shay” locomotives (42″ gauge) to a side track with std gauge to retrieve L&N boxcars to supply their store, and set loaded flat cars with lumber.
Thank you very much for the information! I appreciate the input!