"River of ancient ivory"  'Not just floating down a slow river, solo, but exploring it, searching under the surface for signs of  'color' gold and oranges to indicate ivory, sometimes quite deep in 'ice cold' clear 

water."  "Occasional fish,  fan tailing,  Arctic Char, Grayling and Northern Pike...and a nice Woolly Mammoth Tusk buried in gravel just under the boat."