Before the well-known Western Pacific Railroad finished an alternate transcontinental railroad route in 1909, California had another Western Pacific, organized in 1862 to build a railroad connecting the Central Pacific in Sacramento with San Jose . This first Western Pacific purchased ten locomotives for its railroad construction, lettered from, "A" to "J." Our engine was built for the Western Pacific in 1864 by E.S. Norris in Lancaster, Pennsylvania; it was lettered "G" and nicknamed "Mariposa." By 1867, the Western Pacific had run out of money, which halted construction until the railroad was absorbed by the Central Pacific.
The "Mariposa" became the second Central Pacific #31 in 1869, replacing the first #31 which had blown up in Nevada earlier that year. After forty years of service on the Central Pacific under various numbers (including number 1193), the ex-"Mariposa" was sold to the new and fledgling Stockton, Terminal and Eastern in 1914. ST&E service began on September 5, 1910, on a road built eastward from Stockton by a conglomerate of San Joaquin County farmers, merchants, and promoters. Surviving its early years of poor management, and weathering the up-and-down fortunes of the agricultural industry, ST&E is still an active railroad today. ST&E #1 ran continuously until its donation in 1953 to Travel Town.