Staack, J. G. (1878- ) United States of America. Geological Survey.
Staack, J. G. (1878- ) United States of America. Geological Survey.
Staack, J. G. (1878- ) United States of America. Geological Survey.
Staack, J. G. (1878- ) United States of America. Geological Survey.
Staack, J. G. (1878- ) United States of America. Geological Survey.
Staack, J. G. (1878- ) United States of America. Geological Survey.
Staack, J. G. (1878- ) United States of America. Geological Survey.
Staack, J. G. (1878- ) United States of America. Geological Survey.
Staack, J. G. (1878- ) United States of America. Geological Survey.
Staack, J. G. (1878- ) United States of America. Geological Survey.