Public Domain Lands
Lands the United States obtained by cession from the original states or by treaty or purchase. Only public domain minerals are locatable under the Mining Law; acquired minerals are not.
Detailed Definition
Public domain lands are the lands the United States obtained by cession from the original states or by later treaty or purchase. BLM's Glossary of Surveying and Mapping Terms defines the public domain as "any or all of those areas of land ceded to the Federal Government by the Original States and to such other lands as were later acquired by treaty, purchase or cession, and are disposed of only under the authority of Congress."
How the public domain was acquired
The glossary's entry for original public domain acquisitions covers lands obtained "by cession from the 13 Original States (1789-1802), by the Louisiana Purchase (1803), by the cession from Spain (1819), by the occupation of the Oregon Territory (1846), by the Mexican Cession (1848), by the purchase from Texas (1850), by the Gadsden Treaty (1853), and by the purchase of Alaska (1867)."
Vacant, unappropriated, and appropriated
The glossary separates public domain still in federal hands from land already taken up. Vacant and unappropriated public domain lands are those that "have never left Federal ownership and have not been reserved, withdrawn, dedicated or set aside for a specific purpose." Appropriated public lands are "Original public domain lands which are covered by an entry, patent, certification, or other evidence of land disposal."
Why it decides where mining claims go
BLM's page on locating a mining claim says: "Only public domain minerals are locatable minerals (those minerals that have never left federal ownership). Reconveyed minerals are considered public domain minerals under the mining laws. Mining claims cannot be staked on acquired minerals; a prospecting permit (43 CFR 3500) is required to prospect for acquired minerals."
Acquired lands
The glossary defines acquired lands as "Federal lands obtained by purchase, condemnation, exchange, or gift under laws other than public land laws." BLM's brochure "Mining Claims and Sites on Federal Lands" says minerals that are typically locatable, when found on lands acquired under the Mineral Leasing Act for Acquired Lands of 1947 or on American Indian reservations, "are subject to lease only."
Split estates
The public domain can be the minerals alone. BLM's rules define split estate lands as "those lands where the United States owns the mineral estate as part of the public domain, but not the surface" (43 CFR 3830.5). BLM's page says of Stock Raising Homestead Act lands: "The surface is fee, but the minerals are public domain." Mining claims there follow separate procedures (43 CFR 3838).
Public domain versus public lands
The terms overlap but differ. FLPMA's "public lands" include land administered by BLM "without regard to how the United States acquired ownership" (43 U.S.C. 1702(e)), so they can include acquired land. See Federal Lands.
Why it matters in mining claim research
Federal ownership alone does not make ground locatable; one tract may be public domain and its neighbor acquired. Research confirms how the United States holds the minerals, using the master title plat and the historical index for the township, before treating any tract as open to mining claims.
Related Terms
BLM (Bureau of Land Management)
The Bureau of Land Management, the Interior Department agency that manages the federal mineral estate and records and maintains unpatented mining claims and sites.
Mining Law of 1872
The act of May 10, 1872, that opens valuable mineral deposits on federal land to exploration and location, and still governs mining claims for locatable minerals.
Open to Entry
Federal land that is open to the location of mining claims and sites under the General Mining Law, because it has not been withdrawn or segregated from mineral entry.
Federal Lands
Lands owned by the United States. For mining claims, BLM's rules define federal lands as land owned by the United States and subject to location under the General Mining Law.
State Trust Lands
Land granted by Congress to a state, usually at statehood, and held in trust to earn revenue for schools and other beneficiaries. It is state land, not federal land open to mining claims.