Trivia: The hat band on John Wayne's hat once belonged to Gary Cooper. It was a gift to John from Cooper.
Trivia: John Wayne won his only Oscar for his performance as Rooster Cogburn in this movie.
Trivia: The famous shoot out between Duke and the outlaws in the valley was done twice. The long shots and most of the riding was done for Duke by his stunt double Chuck Roberson. Duke came back an did all the close ups on a horse being pulled by a camera.
Trivia: For good luck, John Wayne wore a new eye patch every day.
Answer: The mountain in the background appears to have two vertical grooves down the surface facing the camera. Those grooves are far too wide to be ski trails. They are simply a natural part of the mountain. Mountains are subjected, over hundreds of thousands of years, to a variety of natural forces, such as wind erosion, water erosion, tectonic shifts and earthquakes, just to name a few. These cause mountains to have irregular shapes, and irregular surfaces.
Michael Albert