autumn canada fall landscape panorama rock Yellowknife bench drop drops foam jet nature park power river rocks saavem troubled turbulence turbulent water waterfall boulders cascade cliff conifer descend forest hillside natural plunge pour Rockies Rocky Mountains Tangle Falls tree waterfalls rivulets brook burn damp dark highland moss mossy rapids smooth stream torrent wet basin coruna eu ezaro flow galicia into mouth outlet plant plants Spain America falls south venezuela