The minerals availability system (mas) was formally established by the Bureau of Mines in May 1975 to provide current appraisals of the engineering and economic availability of nonfuel minerals for consideration in the formulation of both domestic and foreign minerals policy. Domestic mineral property reports are developed by the Bureau's four field operations centers, and foreign data are obtained under contract. This site-specific information is subsequently subjected to engineering verification and economic evaluation, and the results are analyzed and published as minerals availability system appraisals. The deposit-specific data are also entered into the computerized mas data base, where a subset of this information, the mineral industry location system (mils), is available to the public in the form of computer graphics and listings. Other mas products are also described. The Bureau's mas personnel are frequently involved in special engineering and mineral economic projects for other federal and state agencies. Mas personnel also work closely with the private sector, both in the area of mining and processing cost estimation, and as a source of nonproprietary mineral deposit information.