Hello Deigh, this is a cool image of the Deschutes. I like how it’s nestled between the foreground and distant shrubbery. To bring those whites out a bit more I would try a Highlights adjustment in the plus direction. I also think the whole scene could benefit from an exposure or brightness increase.
I agree about bringing up the overall brightness a tad. But I’ve been to this general area when the light is quite flat like this… this image brings me back that memory. So I will say this is actually quite accurate representation of my time there (at least from memory).