Making a name for himself in surveying and politics, pioneering Irishman Jasper O’Farrell was Sonoma County’s wealthiest citizen in 1850.

O’Farrell was born in Wexford County Ireland in 1817 and educated in Dublin as a civil engineer. He left his native country at age 24 to join a surveying expedition in South America. By 1843, he made his way up the coast to Northern California were he surveyed the lands that would later become San Francisco. Picking up where Swiss surveyor, Jean Jacques Vioget left off, O’Farrell laid out the original grid pattern for the city and designed the grand promenade that would later become Market Street.

O’Farrell was paid by the Mexican government in land. In 1846, he was granted Rancho Nicasio in Marin, which he exchanged with James Black for the Jonive Rancho in western Sonoma County. He also purchased the Rancho Estero Americano, including land between the present day Freestone and Valley Ford. On this parcel, he established his family estate, named Analy after ancestral lands in Ireland.

By the mid-1800s O’Farrell’s mapping skills were in demand throughout the state. His surveyor’s seal is on the first maps of Benicia, Napa, Petaluma and much of Sacramento Valley. O’Farrell was compensated well for his efforts. The first U.S. Census of California in 1850, shows O’Farrell as Sonoma County’s wealthiest citizen.

O’Farrell was an influential member of the local Irish community. He was a patron of St. Teresa’s Church in Bodega and served Sonoma and Mendocino counties as state senator. In 1862, he was the Democrats’ (unsuccessful) candidate for lieutenant governor and was appointed State Harbor Commissioner for San Francisco. He died in 1875, leaving eight sons and daughters. O’Farrell descendants can be found throughout Sonoma County to this very day.

Columnist Gaye LeBaron contributed to this report.