A mining claim is a parcel of land for which the claimant has asserted a right of possession and the right to develop and extract a discovered, valuable, mineral deposit. This right does not include exclusive surface rights (see Public Law 84-167).
There are three basic types of minerals on federally-administered lands: locatable, leasable, and salable. Mining claims are staked for locatable minerals on public domain lands.
Locatable minerals include both metallic minerals (gold, silver, lead, etc.) and nonmetallic minerals (fluorspar, asbestos, mica, etc.). It is nearly impossible to list all locatable minerals because of the complex legal requirements for discovery.
Types of Claims
Lode Claims - Deposits subject to lode claims include classic veins or lodes having well-defined boundaries. They also include other rock in- place bearing valuable minerals and may be broad zones of mineralized rock. Examples include quartz or other veins bearing gold or other metallic minerals and large volume, but low-grade disseminated gold deposits. Descriptions are by metes and bounds surveys beginning at the discovery point on the claim and including a reference to natural objects or permanent monuments. Federal statute limits their size to a maximum of 1500 feet in length, and a maximum width of 600 feet (300 feet on either side of the vein).
Placer Claims - Placer claims are defined as "...including all forms of deposit, excepting veins of quartz, or other rock in-place." In other words every deposit, not located with a lode claim, should be appropriated by a placer location. Placer claims, where practicable, are located by legal subdivision (aliquot part and complete lots). The maximum size is 20 acres per locator, and the maximum for an association placer is 160 acres for 8 or more locators. The maximum size for a corporation is 20 acres per claim. Corporations may not locate association placer claims unless they are in association with other locators or corporations as co-locators.
Types of Mineral Entries
Mill Sites - A mill site must be located on "non-mineral lands" and must be noncontiguous to the lode or placer with which it is associated. Its purpose is to support a lode or placer mining operation. A mill site must include the erection of a mill or reduction works and/or may include other uses in support of a mining operation. Descriptions are by metes and bounds if on unsurveyed land and by legal subdivision if on surveyed lands. The maximum size is 5 acres.
Tunnel Sites - A tunnel site is a subsurface right-of-way under Federal land open to mineral entry. It is used for access to lode mining claims or to explore for blind or undiscovered veins, lodes, or ledges not currently claimed or known to exist on the surface. A tunnel site can be up to 3,000 feet in length.
Provisions of the Mining Law allow for the development of local rules that are consistent with federal law. Therefore, individual states can have their own manner of locating and recording mining claims, tunnels sites, and mill sites. Always check with the appropriate state for state-specific laws and regulations.