I first saw these animals when I was about 12 years old--in 1956--when the first big interstate highways were being completed across the U.S. My family was driving through the rolling hill prairies of the western U.S., and a herd of about 50 pronghorn (aka antelope) ran
en masse in the grassland alongside our station wagon. The were in perfect, graceful unison, flowing over the undulations in the landscape, as though they were one organism racing us--a phenomenon that has been long reported in the literature. They ran faster than my father drove, and after they got far ahead of us, they veered away from the road into the open prairie. Ever since then, they have been one of my favorite animals, but now both the large herds and open spaces are rare.
Here are some more photos as a continuation of my previous post, all taken this spring near Yellowstone National Park:
1. This solitary male is standing in lush grass, but was foraging on the hidden broadleaf herbs (forbs). I didn't challenge him to a race, but he amiably trotted alongside my vehicle.

2. At this time of year, most of the pronghorn roam in separate herds of all males and all females plus fawns. Within the male bands some animals group in twos and threes, like these almost identical males.

3. During midday, the pronghorn settle down to chew their cud. If they are in their usual sagebrush habitat (seen in the backgrounds of all the last two photos), the pronghorn disappear from view. This is the first time I have been able find and photograph a sitting pronghorn in the open.
