A bison wanders through snow in Yellowstone Park near Tower Junction in 2017 – Jacob W. Frank, NPS

A bison wanders through snow in Yellowstone Park near Tower Junction in 2017 - Jacob W. Frank, NPS

A bison wanders through snow in Yellowstone Park near Tower Junction in 2017 – Jacob W. Frank, NPS

A bison wanders through snow in Yellowstone Park near Tower Junction in 2017 – Jacob W. Frank, NPS