The summer has brought visitors too who are enjoying Yellowstone at its most vibrant. As the sun now starts to get lower in the sky, the rich colors make this one of the best times to see the geysers.

 

On the grasslands the good times are already over. These bison are making the most of the grazing, but it is now dry and parched. From now on they will have to rely heavily on stored fat to keep them going, as these meadows become covered in more than four feet of snow.

 

Others are already thinking of leaving. Pronghorn evolve/ to outrun a now extinct North American cheetah, and so are the fastest antelope on earth. But unlike / bison, their light-weight bodies can't store enough energy to keep them here through the winter. So now they must head out. Their journey will be the longest of all.