The Southern Emigrant Trail should not be confused with the Applegate Trail, which is part of the Northern Emigrant Trails. Southern Emigrant Trail, also known as the Gila Trail, the Kearny Trail, Southern Trail and the Butterfield Stage Trail, was a major land route for immigration into California from the eastern United States that followed the Santa Fe Trail to New Mexico during the California Gold Rush. Unlike the more northern routes, pioneer wagons could travel year round, mountain passes not being blocked by snows, however it had the disadvantage of summer heat and lack of water in the desert regions through which it passed in New Mexico Territory and the Colorado Desert of California. Subsequently, it was a route of travel and commerce between the eastern United States and California. Many herds of cattle and sheep were driven along this route and it was followed by the San Antonio-San Diego Mail Line in 1857–1858 and then the Butterfield Overland Mail from 1858–1861. History of the Route 1846–1848: Kearney, Cooke, and Graham In October 1846, General Stephen Watts Kearny and his dragoons with their scout Kit Carson found the route over the mountains from the El Camino Real de Tierra Adentro on the Rio Grande, via the Santa Rita mines to the Gila River which he then followed to the Colorado River, at the Yuma Crossing where he crossed the river and then the Colorado Desert to Southern California. This was known as the Gila Trail. One month later, Colonel Philip St. George Cooke and the Mormon Battalion with wagons Kearny could not take across the mountains of New Mexico, followed a route south along the west bank of the Rio Grande from where Kearny had left the river, to a point just north of what later became the site of Fort Thorn. There Cooke left the Rio Grande, establishing a wagon road that reached far southwest through the Guadalupe Pass and then west just south of the current border with Mexico then west to and beyond modern Agua Prieta, before turning northward via the San Pedro River, then west to Tucson. Linking there with the Sonora Road to California established by Juan Bautista de Anza in 1774, they marched on a three-day journey north over the desert before linking up with Kearny’s route on the Gila River just east of the Pima Villages. Cooke followed the Anza–Kearny route westward