In December 2013 Marathon Petroleum, Ohio's largest refiner, announced they would build a new Utica Shale pipeline, called Cornerstone (see Marathon Petroleum’s Newly Announced “Cornerstone” Utica Pipeline). Cornerstone will stretch nearly 50 miles from the MarkWest cryogenic processing plant in Cadiz, OH, heading northwest and connecting to M3's fractionator plant in Scio and M3's cryogenic