The Bureau of Mines investigated the availability of the land in south-central Alaska for exploration and mineral development of locatable minerals under state or federal laws. The land ownership for an area of nearly 72.5 million acres in south-central Alaska was divided into 3 availability categories and 15 subcategories. In July 1985, 31.0 million acres of the study area were available for mineral exploration and development, 6.2 million acres were available with restrictions, and 35.3 million acres were unavailable. About 23.6 million acres in the study area are underlain by mineral terranes. About 9.9 million of the 23.6 million acres are available for mineral entry, 2.4 million acres are available with restrictions, and 11.3 million acres are unavailable. While much of the land currently classified as unavailable will be reclassified once it is conveyed to the state or to native corporations, about 22% of the unavailable lands underlain by mineral terranes are now federal parks, preserves, wildlife, refuges, wild and scenic rivers, and military lands, all of which are considered permanently unavailable for mineral exploration and development.