A barefoot woman stumbles through the snow of northwest Wyoming, collapsing at last, face-down, in a remote stretch of the 2.3 million-acre Wind River Indian Reservation. The nighttime scene, which opens the new film “Wind River” (premiering in Denver Aug. 11), is as cold and context-free as it gets. But we know from the Sundance Film Festival, Cannes and director Taylor Sheridan’s other work (2015’s “Sicaro,” and last year’s Oscar-nominated “Hell or High Water” — both of which he wrote) that whatever this is, it’s not going to be pretty. Beautiful in a severe, chilling way, sure.