Yellowstone and the entire Greater Yellowstone Ecosystem embody the country’s wilderness. The scant roads that incise the park’s interior merely give us a glimpse of the wildness that hides beyond all we can see. On the worst days, a beautiful landscape unfurls as far as the eye can see. Low hills peppered with evergreens and the occasional aspen grove give way to higher mountains that still have snow even as late as the end of May. Below the hills, water cuts draw draws turn into creeks, and creeks turn into rivers as the water that falls on the park and pulled by gravity, cuts and cleaves its way across the landscape, ever-shaping the land.
Over time, the creeks and rivers create large valleys whose deep soils grow the grass and forbs that sustain ungulate biomass that rivals any you’ll see in the lower 48 states, much less the rest of the world. While the migration is relatively short, a migration exists here nonetheless. As the spring thaw commences and the snow wanes from the valleys, temporarily displaced herds of bison, elk, and pronghorns come to greener pastures to graze and give birth to a new crop of offspring that will ultimately populate these hills and valleys.