Southern Pacific Railroad of Mexico

In 1898 the Santa Fe leased the Sonora Railway to the Southern Pacific in return for the latter railroad's line from Needles to Mojave, California.

This arrangement continued until December 1911, when the Southern Pacific purchased both the Sonora Railway and the New Mexico and Arizona.

[3] Owned by the Southern Pacific Company, which operated a highly profitable railroad system north of the border, the SP de Mex transported millions of passengers as well as millions of tons of freight over the years, both within Mexico and across its northern border.

Daniel Lewis (2007) reports it rarely turned a profit, and contends that SP executives, urged on by the media of the day, operated with a reflexive imperialism that kept the company committed to the railroad long after it ceased to make business sense.

[5] When the SP of Mexico was absorbed into the Ferrocarril de Pacifico El Yaqui took the numbers #1 northbound, #2 southbound.