Spanish European settlers brought horses to the American Southwest. Native Americans obtained horses from the Spanish and they too acquired the skills to ride and manage them. From a trade center in what is now Santa Fe, New Mexico, horses started to spread slowly into other parts of North America. Comanche people are thought to be among the first tribes to obtain horses from the Spanish. By 1742 there were reports by white explorers that Crow and Blackfoot people had horses. Horses became an essential part of the lives and culture of Native Americans, especially the Plains Indians who viewed them as a source of wealth and used them for hunting, travel, and warfare. In the 19th century, horses were used for many jobs. In the west, they were ridden by cowboys for handling cattle on the large ranches. In cities horses were used for transporting people via carriage and horse-drawn public transport. At the start of the twentieth century, the United States Department of Agriculture began to establish breeding farms for research to preserve American horse breeds and to develop horses for military and agricultural purposes. After the end of World War I, the increased use of mechanized transportation resulted in a decline in the horse populations. Wild horses still roam freely over parts of New Mexico where herds can be seen alongside the Sandia Mountains and the Rio Grande corridor. New Mexico has several federally-protected wild horse populations. The largest and best known mustang herd ranges are between the Jicarilla Wild Horse Territory in the Carson National Forest and the Carracas Mesa Herd Management Area managed by the Bureau of Land Management. A second herd lives in eastern New Mexico in the Border Atravesado where mountain lions help keep the small population in check. Two additional populations live in the Caja del Rio and Jarita Mesa Wild Horse Territories. Federally-protected wild horses live on less than one percent of federal land in New Mexico.