What did James Marshall build for John Sutter?

James Marshall built a sawmill for John Sutter in 1847, located near the American River in California. This sawmill was intended to provide lumber for Sutter's agricultural and industrial enterprises. However, the discovery of gold in the riverbed near the mill in early 1848 ultimately led to the California Gold Rush, shifting the focus from lumber to gold mining and dramatically altering the region's economic landscape.