Any horse-crazy girl born in the last 50 years or so can remember Marguerite Henry's Brighty of the Grand Canyon, a story of a wild burro who played in the Canyon, hung out with President Roosevelt and fought off a mountain lion all by his fuzzy little self. In the next thought, she'll probably recount Henry's Mustang: Spirit of the West, the true story of the woman who first brought the plight of America's wild horses and burros to the attention of folks from coast to coast, and finally, to Congress. If the aforementioned girl were so compelled, she could actually still glimpse the descendants of Henry's horsey subjects in the deserts and mountains of Arizona today, and it's the short, shaggy burro rather than his more majestic mustang cousin, who is really the equine star of the Arizona desert scene.
There are roughly 40,000 wild horses and burros roaming the American West today, 
mostly in California and Nevada, with a few herds along Arizona's western border. While the wild mustang has become a symbol of the west, their history is a little vague. By anyone's best guess, today's mustang is the result of breeding among escaped horses of the Spanish explorers and Mexican missionaries of the 15th and 16th centuries, later pioneers and cavalry troops, with a few plain ol' domestic farm horses thrown in. The burros have a similar lineage, but it was the mining and prospecting activity of the late 1800s that is probably responsible for most of Arizona's wild burro population today. With its sturdy build and incredible capacity for hard work in hot desert climates, the burro was the partner of choice for work in big mines and by individual prospectors in the lower Colorado River basin. When mining slowed around the turn of the century, burros escaped or were abandoned into the surrounding hills, where, given their heritage that goes back to the deserts of North Africa, they felt right at home.
