That year, the mine produced 10,151 tons of concentrated ore, and in 1917, it produced 22,612 tons.Ernest F. Burchard, Iron Ore, Pig Iron and Steel,Mineral Resources of the United States 1917, Part I Metals, H. D. McCaskey, ed., Government Printing Office, 1921; p. 584. In 1918 the mine produced over 7000 tons before it was shut down because of World War I.James H. Lees, Mineral Production in Iowa for 1917 and 1918, Annual Report, 1918, with Accompanying Papers, Iowa Geological Survey, Des Moines, 1922?; p. 48.
That year, the mine produced 10,151 tons of concentrated ore, and in 1917, it produced 22,612 tons.Ernest F Burc:hard, Ir:on .Ore, Pig Iron and Steel,Mineral Resources of the United States 1917, Part I Metals, H. D. McCaske.y, ed., Government Pri:nting Office, 1921; p. 584. In 1918 the mine produced over 7000 tons before it was shut down because of World War I.James H. Lees, Mineral Production in Iowa for 1917 and 191,8, Annual Report, 1918, with Accompanying Papers, Iowa Geological Survey, Des Moines, 1922?; p. 48.