“Index of Mining Properties in Pima County, Arizona” is the second of the planned series covering the counties of the State. The first, on Cochise County, was published in 1973 as Arizona Bureau of Mines Bulletin 187. The total mineral output from Arizona for over one hundred years has come from many mines, ranging from major operations to small mines and prospects. The record of those opera tions are scattered in numerous publications of Federal and State agencies, in articles in various technical journals, in public and private reports, and in newspaper clippings. Many such sources are not readily available to persons seeking such information. Thus these indices are designed to provide, in a concise form, as much information on min ing properties as may be found. No attempt has been made to name and describe every mining property that may have been located. The selection has been made by the compiler on the basis of production records, special geologic or mineralogic character, or importance in relation to known or possibly hidden mineral resources. The identification of areas of high probability for mineral that might become economic to mine is impor tant not only from the standpoint of a future national re source but also in planning the best use for the land involved.