danger grit mountain pebbles scree stones cold glacial glacier ice landscape norway river valley canada mountains natural nature range rock Rockies Rocky Mountains snow alpine altitude America baker flora flower high lupine mimulus montane slope usa wild current fast fierce flow green norwegian rapid strong trees water eroded erosion scraped scratched wear worn boulder cloud colorado debris precarious rocky rugged sky summit top unstable austere bare barren bleak desolate dolomites Italy remote severe ski lift slopes stern Coast Mountains conifers destination direction path track trail travel Trek Whistler cliff forbidding grim house refuge view