Moss grows thick on tall old growth trees at Hoh Rain Forest, Olympic National Park, Washington, USA.

Moss grows thick on tall old growth trees at Hoh Rain Forest, Olympic National Park, Washington. Here in one the few temperate rain forests in the USA, annual precipitation ranges from 141 to 165 inches (12 to 14 feet or 360 to 420 cm). Summers are relatively dry in comparison to the rest of the year.