Santa Margarita is an unincorporated town is located in San Luis Obispo County, California founded in 1897 near Cuesta Peak and San Luis Obispo along State Route 58. It's one of the most rural areas in San Luis Obispo County The town's name comes from the name issued by the Mexican government to describe the area when it was a land grant inside Alta California. It is home to a Mexican mission named Santa Margarita Asistencia. Santa Margarita Lake, a major water source for San Luis Obispo, is located several miles southeast of the town on the Salinas River. It is served by the zip code 93453 and area code 805.
The town is surrounded by the Santa Margarita Ranch, a 15,000+ acre Spanish rancho which is home to the historic Santa Margarita de Cortona Mission Asistencia. Secularized from Mission San Luis Obispo de Tolosa, these lands in the foothills of the Santa Lucia Mountains were originally granted to Joaquin Estrada, who later sold it to the Martin Murphy, Jr. family. Californio culture is still very much alive at the Rancho, which remains in the private ownership of local developers Rob Rossi, Doug Filipponi, and Karl Wittstrom. It remains a working stock ranch and is also now home to the Ancient Peaks Winery and the Pacific Coast Railroad Company, a narrow gauge steam heritage railway.