Columbia is a former California Gold Rush boom town that lives on as a state-preserved historic park and a National Historic Landmark that preserves the original, gold-rush-town flavor of the town, once dubbed the "Gem of the Southern Mines. " Founded in 1850 by Mexican gold miners, it is in Tuolumne County, California, United States. Although only about 2,000 people now live in this region near Sonora, California, at its height it was California's second-largest city. It was even considered briefly as a site for the state capitol of California. In 1854 the bulk of the town burned down and was re-built with brick and iron structures that survive to this day. Columbia's main street, part of the Columbia State Historic Park, is closed to automobile traffic but is open to horses and carriages, as well as pedestrians. The town, now technically a census-designated place (CDP), is located along State Route 49 just north of Sonora. The US Postal Service ZIP code for the community is 95310. Wired telephones in Columbia work out of the Sonora central office. Major points of interest in the area include Columbia Community College, a two-year, community college. Columbia Airport includes one 4,670-foot (1,420 m) runway and is busy with firefighting aircraft during summer. The annual Columbia Fire Muster here is often the earliest of California's summer musters.