In 1848, when gold was discovered by James W. Marshall at Sutter's Mill in Coloma (located some 50 miles (80.5 km) northeast of the fort), a large number of gold-seekers came to the area, increasing the population.
En 1848, cando James W. Marshall descubriu ouro en Sutter's Mill, en Coloma (situado a unhas 50 millas (80.5 km), ao nordeste da fortaleza), un gran número de buscadores de ouro chegaron á zona, aumentando a poboación.