The Grand Trunk Pacific/National Transcontinental route remained intact for only a few years during World War I. The GTP had built through the Yellowhead Pass on a route paralleled later by Canadian Northern, but near Mount Robson, GTP headed toward Prince Rupert. Prince Rupert was one of several possible Pacific termini for the line. Originally, Port Simpson on the Alaska border was selected, but a border dispute with the United States in the early 20th century left Canada concerned about the defensibility of any Pacific rail terminal, and the terminal for GTP was moved south to Prince Rupert. That selection potentially saved a day of steaming for ships to or from Asia.