The Conquistadors brought horses from the Iberian Peninsula to North America in the 1500s. Centuries later, the descendants of those Spanish horses bred with the stock introduced by Northern Europeans, and the American Mustangs were born.
Mustang, as a term, simply refers to a horse of mixed breeding, but over the years they have become iconic symbols of the American West. As pioneers put down roots, the Mustangs where caught, tamed and trained to do the heavy lifting of homesteading from Washington to Texas.
Eventually tractors and trucks took over the dirty work and Mustangs faded back into the wilderness. The Federal Government estimates that there are as many as 30,000 wild horses roaming the western public lands and with no natural predators, herds can double in as little as four years.
To keep their numbers under control, the Bureau of Land Management regularly holds round ups, transferring the wild animals to federal holding pastures. Some are trained and later adopted, while a lucky few find their way to the 5,000 acre Wild Horse Sanctuary in Modoc County in Northern California. There they roam free on the foothills of Mount Lassen, visited only occasionally by human tourists on sightseeing expeditions.