The influence of American settlement ultimately led to the Bear Flag Revolt, after which California became part of the United States in 1848. In the same year, gold was discovered on the American River, starting the California Gold Rush. Although gold mining was initially concentrated on the American and other rivers to the north, attention was drawn to the Stanislaus in August 1848 after a Native American party under Charles Weber discovered gold on the river. The entire mining camp of Dry Diggings (near today's Placerville), about 200 men in all, packed up and headed south to the Stanislaus River, and as news spread throughout the Gold Country, hundreds more arrived. Many miners traveling from the eastern United States arrived in California via the Sonora Pass, at the headwaters of the Middle Fork of the Stanislaus River. By 1849, as many as 10,000 miners had reached the Stanislaus River country.