The first bituminous coal mine in the area was opened shortly after 1853 by Robert Seevers, who drove a drift into a 4-foot coalbed in an exposed creek bank east of town. Initially, coal was mined entirely for local consumption, but with the arrival of the railroads, coal from the region was shipped widely. In the 1880s, more than one million tons of was mined in the county from 38 mines. By 1887, the report of the state mine inspector listed 11 coal mines in or very close to Oskaloosa. By 1895 the coal output of Mahaska County surpassed that of all other Iowa counties, and production had reached more than one million tons per year. In 1911, coal mining was reported to be the primary industry in the region. In 1914, the Carbon Block Coal Company of Centerville produced more than 100,000 tons of coal, ranking among the top 24 coal producers in the state.