Mustangs, found roaming the western United States, are descendants of Spanish domestic horses brought to the Americas in the 16th century by explorers. Their name originates from the Spanish words “mestengo” and “mostrenco,” which, according to Oxford Learner’s Dictionaries, translate to “wild or masterless cattle.”

While often called “wild horses,” the American Museum of Natural History (AMNH) classifies mustangs as feral because they descended from domesticated animals. Despite their free-roaming existence, they are also kept and ridden by humans. Horse Canada notes that mustangs possess muscular builds and durable hooves, making them well-suited for scouting and trail riding.

The Equus genus, which includes horses, originated in North America approximately 4 million years ago before spreading globally. The last truly wild horses in America disappeared around 10,000 years ago, likely due to a combination of climate change and human activity, as previously reported by Live Science.

Like other horses, mustangs are measured in hands, typically standing between 14 and 15 hands high, equivalent to 56-60 inches (140-150 cm). America’s Mustang program estimates their weight to be around 800 pounds (360 kg).

Mustangs exhibit a wide array of coat colors, encompassing the full spectrum found in horses, according to Oklahoma State University. Common colors include bay (reddish-brown) and sorrel (chestnut), and they can also display various patterns of patches, spots, and stripes.

Regarding speed, Horse Canada notes that most mustangs can gallop at 25-30 mph (40-48 km/h), with one recorded instance of a mustang reaching 55 mph (88 km/h) over a short distance.

Mustangs, primarily grazing animals, inhabit the grasslands of the western United States, consuming mainly grass and brush. The U.S. Bureau of Land Management (BLM) manages the free-roaming wild horse and burro populations across 26.9 million acres (10.9 million hectares) of public land, encompassing ten herd management areas in Colorado, Nevada, Arizona, California, Idaho, Montana-Dakotas, New Mexico, Oregon-Washington, Utah, and Wyoming. According to Smithsonian Magazine, feral horse populations also exist along the Atlantic coast and on islands such as Sable, Shackleford, and Assateague.

Mustangs organize themselves into social units called herds, typically composed of one stallion, approximately eight mares, and their offspring; however, different herds may combine in times of danger, as noted by the Humane Society. A mare leads each herd, alongside a stallion typically over six years of age. In the face of threats, the lead mare guides the herd to safety, while the stallion defends them.

Mustang mares, like those of other mammals, give birth to live young, known as foals, after an 11-month gestation period, typically foaling in April, May, or early June, according to “The American Mustang Guidebook.” This birthing timeframe allows the foals ample time to mature before the onset of winter.

While domestic horses, including mustangs, generally live for 25 to 30 years in captivity, with some exceeding 40 years, wild mustangs inhabiting public lands in the western United States tend to have shorter lifespans, although some have been recorded to live up to 36 years.

Mustangs, the wild horses of North America, are generally a blend of various breeds due to the intermingling of the original Spanish horses with other domestic breeds over time, including draft horses and Thoroughbreds, as noted by National Geographic.

The extent of this interbreeding varies across different mustang populations, resulting in some groups retaining a closer genetic link to their Spanish ancestors than others. Kiger mustangs in Oregon, for instance, live in small, isolated herds, allowing them to maintain a bloodline predominantly descended from the early Spanish horses and exhibiting less mixing with other breeds.

Mustangs, while inherently wild, are capable of being tamed and ridden, although those captured directly from the wild require a more extensive training period compared to horses bred in captivity due to their unfamiliarity with human interaction, as noted by Horse Canada. During the Wild West era, specifically from the 1850s to 1900, cowboys known as “mustang runners” would capture, tame, and subsequently sell these horses.