|  | Abstract: | Three-page typescript report from Holt to his partner, a Mr. Brock, about the Santa Eulalia group of mines near Sombrerete District, 
      								state of Zacatecas, Mexico, dated August 11, 1927. Included are four blueprints: an assay map, a geological plan, a surface plan, and a map; 
      								and also a hand-drawn map of important mining camps in the area. |  |