From abstract: The Santa Rita mining area (pl. 1), covering 35 square miles of semiarid mountainous land, lies within the Silver City 30-minute quadrangle, Grant County, N. Mex., and includes the most productive part of the Central or Hanover mining district. Ore was produced in this district as early as 1804 and production continued intermittently for a century before the developments were undertaken that led to large-scale copper mining, which began in 1912. The output of zinc, lead, and iron increased markedly about the same time.