Scheme for working the City Deep Mine at a depth of 7000 ft.,, 1921

Scheme for working the City Deep Mine at a depth of 7000 ft.,, 1921, Box: 259, Folder: 15. Saint John d'El Rey Mining Company Records, 1984-12. Benson Latin American Collection, The University of Texas at Austin. https://archives.lib.utexas.edu/repositories/4/archival_objects/346014 Accessed September 26, 2026.