What we think of as classic 'Western' landscape is actually a bit of desert with rocks in, just inside a 30 miles-from-Hollywood union rule - which isn't much like Montana/Dakota/Idaho/Wyoming.
When I was told about Vasquez rocks, I was amazed how often it appeared then remember that the frog sound used in movies is just the ribbit sound frogs make is just from an area of southern California
Reuse of Western locations, notably Vasquez Rocks is a factor:
https://en.wikipedia.org/wiki/List_of_productions_using_the_Vasquez_Rocks_as_a_filming_location
Also seen in recent Westworld.
What we think of as classic 'Western' landscape is actually a bit of desert with rocks in, just inside a 30 miles-from-Hollywood union rule - which isn't much like Montana/Dakota/Idaho/Wyoming.