What is the name of John Waynes movie shot in Durango. The plot involved horse rustlers fom USA to Mexico?

The John Wayne movie you are thinking of is "Rio Grande" (1950).

While not entirely focused on horse rustlers, the film's plot revolves around a US Army cavalry regiment stationed along the Rio Grande, battling both Apaches and horse thieves, who cross the border from Mexico.

Here's why it fits your description:

* John Wayne: Stars as the commanding officer, Colonel Kirby Yorke.

* Durango: Though not explicitly mentioned, the film was shot in Monument Valley, which was a common location for Westerns set in the American Southwest and Mexico.

* Horse Rustlers: The film features horse thieves who cross the border, stealing horses from the US Army.

Hope this helps!