Arizona Gold Placers and Placering was published by the Arizona Bureau of Mines in conjunction with University of Arizona as Bulletin 118 in 1922 and eventually became what it is today as bulletin 142 in 1937 fourth revised edition. This book covers all of the known Placers in Arizona by county. Additional information on the placers, their formation, History, Geology, production and locations are included. In addition, best types of recovery for these placers are discussed.