These antelope were photographed in Presott, Arizona near Granite Mountain. This young male was in the company of 4 females. They were't spooked when I first noticed them lying and grazing on a small hillside. But as I moved closer to them, they started to move off along the hillside. Notice that the hairs of the rump of a proghorn can be held erect to produce a white flash warning signal of danger visible for many miles. As the fastest North American mammal, pronghorns can reach speeds of 60 miles per hour. At high speed they cover the ground in great strides of 14 to 24 feet, and are known to run for long distances at speeds of 30 to 40 miles per hour.