 In Tucson, the Survey maintains a geological library comprising more than 15,000 volumes and approximately 100 linear feet of mine files that include newspaper clippings, maps, mine schematics and mine reports; it also maintains a small core repository of donated rock core.In addition, AZGS archives well cuttings of more than 1,000 oil and gas wells on behalf of the Arizona Oil and Gas Conservation Commission.The AZGS Phoenix branch maintains tens-of-thousands of mine maps and reports acquired in 2011 when the Arizona Department of Mines and Mineral Resources merged with AZGS.