In this scene, Bierstadt has captured that fascinating stretch of land that rises from valley's edge to the high mountains.  This is not nature as a backyard garden.  This is clearly wilderness:  the view is expansive, no where can be seen a sign of man - and just to make sure you haven't missed the artist's intention: a bear is eating its kill in the left foreground.  

While this is wilderness pure and simple, Bierstadt hasn't imbued the painting with the qualities of the sublime:  the color palette lends warmth to the scene and there is nothing fearsome and dangerous about it. 

The rugged, snow-covered mountains which could represent danger are way in the distance and only add to the overall beauty of the scene.   Elk drink from the river.   The bear, though it represents a state of wildness, is not unduly intimidating and almost blends in with the scenery.  There is a balance of trees and open grasslands, gentle lands and rocky outcroppings.   You almost want to curl up under one of the trees, lay back and soak it all in - that is, as long as you can stay a respectful distance away from the bear.