The first publication of the Arizona Bureau of Mines on Arizona Gold Placers was written by Mr. M. A. Allen, when Geologist with the Bureau, and appeared in 1922 as Bulletin 118. It was mainly a compilation of data already in print, but scattered and difficult to find. The stock of this bulletin was exhausted in four years. Mr. Eldred D. Wilson, Geologist with the Bureau, was then commissioned to re-write the bulletin, adding what new data could be obtained. Assisted by Mr. W. R. Hoffman in the field and further aided by the advice and suggestions of Dr. Carl Lausen, then Geologist with the Bureau, Mr. Wilson completed his work in the summer of 1927 and a large edition was published at once as Bulletin 124. Conditions with which everyone is familiar developed within two or three years and so much interest was shown in gold that the demand for this bulletin was extremely heavy and the supply was exhausted before June of last year. A new and greatly enlarged bulletin, No. 132, was prepared at that time, and, although five thousand copies were printed, they have all been distributed. The present bulletin does not differ radically from No. 132, but many parts of that bulletin have been re-written and an attempt has been made to bring the information obtained therein up to date. Mr. Eldred D. Wilson made the field investigations required to secure this new data, and at least a dozen additional districts are described in the present bulletin. 148 p.