A member of the Teton pronghorn herd stands in fresh autumn snow at Antelope Flats. The first snow of the season started the pronghorn moving on their annual migration to the Upper Green River Basin, a journey over 120 miles. It is the longest land mgration in the lower 48 states and some pronghorn travel up to 170 miles for winter range. After spring calving, the Teton herd returns to the National Park. Photo by Dave Showalter.