Santa Margarita de Cortona was founded in 1775 as part of the original Spanish mission system. Its asistencia, in fact, has been considered a lost mission. Santa Margarita Ranch was later founded from a Mexican land grant. In 1889, the arrival of the Southern Pacific Railroad, with its terminus in Santa Margarita, created a boomtown with dance halls, blacksmiths, hotels, pool halls, saloons, and a jail. And with the popularity of auto travel half a century later, Santa Margarita was once again revitalized with garages, gas stations, motor inns, restaurants, and bars. It fell into a deep sleep, however, as Highway 101 bypassed the town in the mid-1950s. Landlocked by the 17,000-plus-acre Santa Margarita Ranch, the town has remained frozen in time until recently.