In January 1847, the Mormon Battalion arrived in San Diego. Battalion members helped construct a number of building and public works in San Diego. They then traveled to Los Angeles where they built a fort and raised the first American flag in California. Six discharged battalion members were at Sutter's Mill in northern California when gold was discovered there on January 24, 1848. On their way, they carved an emigrant road that would be used by thousands of westward bound travelers including the gold rush "Forty-Niners."