Gold Is Where You Find It with Olivia de Havilland, George Brent, and Claude Rains. This is a classic farmers vs. non-farmers Western. In this case the non-farmers are hydraulic gold miners. It is set in 1879 and the simple panning and digging of the original California gold rush has been replaced by huge water cannons that turn mountains into silt. The run-off of these operations is destroying the good wheat-farming land downstream. Claude Rains plays the patriarch of a wheat-farming family who leads the agrarians in attempting a peaceful victory over the gold miners via the judicial system. The gold miners are unscrupulous San Francisco fops who drink cocktails instead of straight whiskey and plan to continue at any cost.
This movie is in Technicolor (my fourth, I think) and is directed by Michael Curtiz. I am coming to learn that Curtiz was king of the action sequence. He was the second director of The Adventures of Robin Hood and you can really see the increase in energy half-way through that movie. This movie ends with George Brent blowing up a dam to destroy the mining camp.