The population of feral horses, or mustangs, greatly decreased in the United States during the 20th century. The modernization of the countryside, extreme weather conditions, indiscriminate hunting and human pressure have all led to the slow demise of wild horses. But in an area of southern Spain, the heritage and lines of the mustangs live on.

From 1493 to 1512 an estimated 500 horses traveled on ships to the Americas. This importation of livestock along with their breeders from the marshland of the Guadalquivir River on Spain’s southern Atlantic coast had a clear impact in the New World. In 1971, Congress recognized the mustang as a living symbol “of the historic and pioneer spirit of the West” that continues to contribute to the diversity of lifeforms within the United States and enrich the lives of Americans.

That spirit and the sense of animal union with man is still alive in the mustangs’ point of origin, the marshes of Doñana National Park in the western region of Andalusia, the southern portion of the Iberian peninsula that also embodies Seville.

The National Association of Cattle Breeders Marismeño in Spain was formed by descendants of people who, in ancient times, created a covenant between the god of the seas and horses, and now works to preserve the way of life for the last population of feral horses living in freedom.

In 2015, with the aid of the Association of Cattle Breeders Marismeño, photojournalist David Rengel documented the “La Saca de las Yeguas,” or “Out of the Mares” festival, an annual event that takes place in Andalusia in late June. The association’s efforts have been crucial toward the preservation of the Retuerta and Marismeño horses, two rare breeds that are some of the oldest in Europe and indigenous to Andalusia. Both have been placed on the endangered species list.

Each year, the horses make the sacred pilgrimage from Doñana National Park, considered the largest ecological reserve in Europe and declared a World Heritage Site by UNESCO in 1994, to the town of Almonte before being paraded through the village of Rocio, a world-famous center of pilgrimage. It is here where the horses’ life is blessed by a priest.