The U.S. decennial census collected the first statistics on mines and mining (as distinguished from persons employed in this field) in this country in 1840 and approximately every 10 years thereafter, through 1940. After 1940, the censuses of mining industries were taken for 1954, 1958, and 1963. Since 1967, mining and minerals establishments have been included in the economic census covering years ending in “2” and “7,” as authorized by Title 13 of the United States Code. Title 13 requires response to the census inquiries and also assures that all information provided by companies in response to the census will be kept confidential and published in summary form only. Thus, the U.S. Census Bureau makes certain that no individual firm’s operations can be identified in its printed reports or public-use electronic products, and agency employees are subject to heavy penalties for violating the law’s confidentiality provisions.

The U.S. Census Bureau collects its data directly from all large firms, usually by mail, and abstracts statistics on employment, payroll, and receipts from federal administrative records for the remaining establishments. Using administrative records relieves many small firms from having to file census returns.

The unit of enumeration for the census is the establishment—generally defined as a single, physical location at which one or more of the following activities takes place: metal mining, coal mining, oil and gas extraction, or mining and quarrying of nonmetallic minerals (except fuels).

The Mining sector of the 1997 Economic Census covered those mining establishments or companies with one or more paid employees. Mining is defined as the extraction of naturally occurring mineral solids, such as coal and ores; liquid materials, such as petroleum; and gases, such as natural gas. The term “mining” is used in the broad sense to include quarrying, well operations, beneficiating (e.g., screening, washing, and floatation), and other preparations customarily performed at the mine site or as part of the mining activity.

The Mining sector distinguishes between two basic activities: mine operation and mining support activities. Mine operations include establishments operating mines, quarries, or oil and gas wells on their own account or for others on a contract or fee basis. Mining support activities include establishments that perform exploration (except geophysical surveying) and/or other mining services on a contract or fee basis.