There was a 1930s movie Frontier Horizon with John Wayne that supposedly followed the story line of LA/Mulholland taking the Owens Valley Water but all the names were changed.
There is a scene from the Frontier Horizon movie in the Cadillac Desert movie which was made in 1997, which was based on the book Cadillac Desert published in '88 &'92.
The other movie on the fight for the Owens Valley water was Chinatown from '74.
Cool, thank you, I’ll look for it!