Sonoma County Points of Interest
Constructed Agostino Pinelli, a highly skilled stonemason from Italy. Pinelli came to Sonoma under a contract from General Mariano Vallejo to extract stone from his land. He later managed a nearby quarry.
Pinelli and his team of eight to ten workers hand-quarried the stone to build the two-story structure. It is celebrated for its Renaissance Revival style and its distinct rock-faced ashlar walls made of local plum stone basalt. The Pinelli family lived upstairs and rented out the ground floor to commercial tenants. In 1916, a single-story extension was added to the north (408 1st Street East) using repurposed lumber from a defunct local schoolhouse.
Source: Sonoma League for Historic Preservation and Sonoma Valley Historical Society

Ashlar masonry is formed using finely dressed stones of same size, shape, and texture laid together in cement or lime mortar of equal size joints at right angles to each other. The joints between the stones are very thin, regular, and of uniform thickness, which make the ashlar masonry very strong and sturdy.
Because it takes time and skill to prepare the finely dressed stones and then build with them, ashlar masonry is most often used for imposing structures like fort, castles, palaces and churches.
Source: The Constructor website.

Italian stonemasons immigrated to Sonoma and Napa counties at the beginning of the 20th century to escape political unrest. Peter Maroni, Natale Forni, Massimo Galeazzi, Angelo Sodini, and others had acquired the skill of cutting hard stone in the quarries of Northern Italy. Stone was quarried in Santa Rosa and Kenwood, dropped from bunkers into horse-driven wagons, and conveyed to building sites where stone was finish cut and set in place. (Source: NRHP nomination form for Railroad Square Historic District in Santa Rosa.)
Many of their structures survived earthquakes, floods and urban renewal and are here today: