On a crisp Monday morning while inspecting a tailrace of John Sutter’s sawmill, James Marshall caught a glimmer of something shiny in the waters of the American River. Eureka! It was gold. That fateful event 170 years ago yesterday (Jan. 24,1848) inspired the largest mass migration in U.S. history.

The Gold Rush brought some 300,000 migrants from across the country and abroad to Northern California in hopes of striking it rich.

Many of purveyors never found gold, but they did find riches of a different kind, settling and developing the golden hills of fertile California.

In Sonoma County, Harmon Heald was among the onslaught of 49ers who decided to stick around. The Ohio businessman started out squatting on the rancho land that eventually bore his name. At the center of Healdsburg was Heald’s general store, offering supplies to farmers or those heading north to pan for gold in the Trinity River.

The Italian-born Simi Brothers, Giuseppe and Pietro, were also Gold Rush immigrants. Their Healdsburg Winery opened in 1881 and is still around today.

But those are just the famous ones, among the ranks were people of all nationalities, races and genders. Many of these transplants where unable to afford the costly return journey by sea or by wagon and decided to hang around.

Click through our gallery to learn more about Sonoma County’s connection to the California Gold Rush.