This is a different kind of herding, as it focusses on horses instead of cattle.
Color Reproduction by Pikes Peak Lithographing Co.
The description states:
A152 — WILD HORSE HERD
Rounding up wild horses required excellent horsemanship, dexterity at roping and infinite patience.
–The image seems a bit more docile and less dramatic than the post card description. These horses are already pretty much under control, as the two cowboys in the foreground have established a rope cordon around the herd as seen by the thin yellow line across the image.
These horses are commonly called wild, but they are better described as feral horses, having descended from domesticated horses abandoned by the Spanish in the 16th and 17th century. Those living on public land are protected now under federal law.
This postcard likely dates to the 1950s.