Old Spanish Trail (trade route)

The Old Spanish Trail (Spanish: Viejo Sendero Español) is a historic trade route that connected the Nuevo México settlements of (or near) Santa Fe with those of Los Angeles and the rest of Alta California. Approximately 700 mi (1,100 km) long, the trail ran through areas of high mountains, arid deserts, and deep canyons. It is considered one of the most arduous of all trade routes ever established in the United States. Explored, in part, by Spanish explorers as early as the late 16th century, the trail was extensively used by traders with pack trains from about 1830 until the mid-1850s. The area was part of Mexico from Mexican independence in 1821 to the Mexican Cession to the United States in 1848.

The name of the trail comes from the publication of John C. Frémont's Report of his 1844 journey (which crossed into Mexico) for the U.S. Topographical Corps, guided by Kit Carson, from California to New Mexico. The name acknowledges that parts of the trail had been known and used by the Spanish since the 16th century. Frémont's report identified a trail that had already been used for about 15 years. The trail is important to New Mexico history because it established an arduous but usable trade route with California.

In 2002 this trail was designated by Congress as part of the National Trails System as Old Spanish National Historic Trail.