There are many laws regarding mining, sales and leasing of the Public Domain in the United States. The Acts presented below are not related to those forms of mining but instead are concerned with the process of Granting discoveries of valuable mineral deposits found on the Public Lands to their discoverer. This Grant effects a transfer of the Public Lands held in trust by the States United in Congress to the locator and discoverer. The extent and nature of that Grant is described within these foundational Acts.
The 1866 Mining Law (PDF 263 kb)
Entitled: An Act granting the Right of Way to Ditch and Canal Owners over the Public Lands, and for other Purposes.
Although the actual title is somewhat misleading, this is the Act that is commonly referred to as the Mining Law of 1866, passed on July 26th of that year.
The 1870 Mining Law
Entitled An Act To amend "An act granting the right of way to ditch and canal owners over the public lands, and for other purposes."
The 1872 Mining Law (PDF 571 kb)
Entitled: An Act to promote the Development of the mining Resources of the United States.
This copy was provided by the Library of Congress as an excerpt of "Statutes at Large" for the 2nd session of the 42nd Congress 1872.
"Statutes at Large" is the publication at the end of each Congressional session, as authorized by Congress, of Statutes enacted during each session.
You will find many more interesting documents at the Library of Congress link below.