Back when Stanley Hall (General Manager for many years) was alive, he and the Kovalchik's aggressively defended the railway against any attempted incursions. Stanley explained to me that the railway owned the property in "fee simple". I assume the Kovalchik's continued to monitor the situation after Stanley passed away.
To change the subject slightly, is there a wye at Saltillo where the Narco branch took off? This would make a logical intermediate end point for operations if the engine or even complete train could be turned there.
Michael Allen