A more thorough explanation:

Mineral entry refers to the right of entry on public land for the purpose of mining valuable mineral deposits. The United States government has reserved all lands that are "valuable for minerals" from disposition under non-mineral statutes, and has made them available for mining purposes under regulations prescribed by law.

For example, if a mining company wants to extract valuable minerals from a piece of public land, they must obtain a mineral entry permit from the government. This permit allows them to enter the land and mine the minerals.

Another example is if an individual discovers a valuable mineral deposit on public land, they may apply for a mineral entry permit to mine the deposit and potentially profit from it.

Overall, mineral entry is an important aspect of mining in the United States, as it allows for the exploration and development of valuable mineral resources on public lands.