In 1870, Congress authorized the survey and sale of placer (a transported mineral deposit) claims for $2.50 per acre.
On May 10th, 1872, the most significant mineral disposal law was passed in the form of the U.S. Mining Laws Act. It accounted for the majority of mineral patents and thousands of mining claims on the public domain and National Forests in the West. This law states:
...that all valuable mineral deposits in lands belonging to the United States, both surveyed and unsurveyed, are hereby declared to be free and open to exploration and purchase, and the lands in which they are found to occupation and purchase, by citizens of the United States....
In spite of efforts to change to some other system such as leasing, this law is still in existence today. However, it was not one of the larger disposal laws. Only 3.1 million acres have been patented since 1866 under these mining laws. In the first 90 years of its existence approximately 35,000 acres per year were patented, and during the last 30 years about 4,000 acres per year have been patented.