The Decline of Columbia By 1860 mining and business were on the decline in Columbia and much of the population had departed. During the 1870's and 1880's numerous vacant buildings were torn down and their sites mined. But Columbia never became a true "ghost town," for its population has long been approximately 500, with as many more living within a radius of two miles. Generally, the remaining buildings retain their original ap- pearance, and Columbia typifies, better than any other in the State, a Gold Rush town. Former Alberding Store, built in 1856