They interchange with CSX, CNNA. and NS. As far as I can see, all three have increased in volume considerably. Of course GDLK has done an admirable job of growing their business overall so it has to go somewhere.
Who would have dreamed of trains headed up with three SD-40's and 140+ cars to and back from Elkhart!
Just a little side note: Whoever labeled up #4206 must have been off in the ozone somewhere. The engine type on at least one side says "SP40-2". Maybe that really means something to WATCO.