lay, respectively, to the east and west of the San Gabriel Canyon mouth. Rancho San Francisquito, Rancho Potrero Grande, Rancho Potrero de Felipe Lugo, Rancho La Puente, and Rancho La Merced were located further south in the San Gabriel Valley. Rancho Paso de Bartolo was situated in the Whittier Narrows area, and Rancho Santa Gertrudes, Rancho Los Coyotes, Rancho Los Cerritos and Rancho Los Alamitos occupied various areas of the coastal plain. California became a U.S. state in 1850, two years after the Mexican–American War. One of the decisive battles of the war was fought on January 8, 1847 on the San Gabriel River, which was the last line of defense for Mexican Californio forces led by Mexican Governor-General José Flores, tasked with defending the pueblo of Los Angeles. American forces, led by General Stephen W. Kearney under Commodore Robert F. Stockton, crossed the river under heavy fire, but were able to force the Californios from their defensive position in under ninety minutes. After taking control of the river, the Americans were able to take Los Angeles on January 10, and the Mexicans surrendered California three days later. This campaign is now remembered as the Battle of Rio San Gabriel. Gold seekers Although it was rumored for many years that Native Americans and Spanish explorers had discovered gold in the San Gabriel Canyon long before California became a U.S. state, gold was first confirmed in the upper San Gabriel River around April 1855, by a party of prospectors who had entered the mountains via Cajon Pass. The Los Angeles Star soon reported of their findings: The river remained quiet for a number of years, as drought conditions reduced streamflow and made placer mining difficult. The winter of 1858-59 was a wet one, and soon hundreds of gold seekers from both Los Angeles County and Kern County further north descended on the river. By May 1859 claims were staked along of the San Gabriel Canyon. In the early days, access to the diggings proved difficult as the rocky San Gabriel River bed was the only way into the rugged mountains. In July 1859 stagecoach service was established to bring in miners and their supplies. Between 1855 and 1902, an estimated $5,000,000 ($ in dollars) worth of gold was removed from the San Gabriel River. Mining along the San Gabriel River began with simple gold panning, but soon developed to more advanced