One of the things that grabs me about these pictures is the atmospheric perspective. Living in the Rockies, I'm more or less surrounded by vistas like these, but the air is so clear that this kind of beautiful shading into the distance simply isn't there. Sometimes, oncoming weather will produce this effect, but it's pretty rare and usually not this gentle. Bierstadt caught the Rocky Mountain version in "Among the Sierra Nevada Mountains." It's not very serene.