Pima County is endowed with many mineral resources, not only copper mines, but also the important products such as sand, gravel, and limestone used everyday in supporting the infrastructure of our cities. It is essential that these mineral resources, and the lands where they occur, remain available for exploration and development. This report presents an assessment of the mineral resources of Pima County based on hard data derived from many experienced geologists working in the private sector and from publications of state and federal government agencies.