Steve Backshall heads south once more and into Yellowstone national park in the USA. This frozen wonderland is home to the continent's most iconic beasts.

Steve and his intrepid crew are in the backwoods of North Carolina, USA, in search of the infamous timber rattlesnake.

Steve Backshall's journey takes him to Texas, where he lowers himself into the depths of one of the most inhospitable environments on earth.