During the past year or two there have been some important developments in the Dubuque district. New lead mines have been opened up, new ore bodies have been discovered, and the Durango zinc mine, the largest in the state, has been still further developed.
Proceedings of the Iowa Academy of Sciences
©1895 Iowa Academy of Science, Inc.
Leonard, A. G.
"Recent Developments in the Dubuque Lead and Zinc Mines,"
Proceedings of the Iowa Academy of Science, 3(1), 64-66.
Available at: https://scholarworks.uni.edu/pias/vol3/iss1/18