Subsequently other stage lines operated along the route until the Southern Pacific Railroad arrived in Yuma, Arizona.
Although it lasted only from 1857 to 1861, the Butterfield route made famous one of the most important roads in the early settlement and development of California and most of it was used in one form or another until today.
That Sonora Road linked with the Kearny Trail was used during the Mexican American War by the U.S. Army.
During the California Gold Rush the route pioneered by Kearny and Cooke with the addition of a road from Warners Pass to Los Angeles became the Southern Emigrant Trail used by American immigrants, and herds of stock from the east in 1849 and for decades thereafter.
From there the route ascended northwest into the Peninsular Ranges, via the San Felipe Station in the San Felipe Valley crossing via Warners Pass to Warner's Ranch, then to Temecula Station and on to Los Angeles, headquarters office and terminus of the Second Division.