American Bison - Yellowstone National Park, Wyoming.

Taken at Yellowstone National Park at sunrise in Hayden Valley.

The American Bison, or also known as Buffalo, are the largest mammal of North America. Males can weigh upwards of 2,000 lbs, and stand 6ft tall.

These animals don't look fast, but can reach speeds of 35 mph. I personally witnessed these animals running, and mistook them for wolves, thats how fast and agile they're.

What makes Yellowstone special with these Bison is that they're direct descendents of Bison who lived their during prehistoric times.

They're territorial animals and that is why Yellowstone works so hard at making visitors aware to keep a distance.