A mining claim is the claim of the right to extract minerals from a tract of public land. In the United States, the practice began with the California gold rush of 1849. In the absence of effective government, the miners in each new mining camp made up their own rules, and chose to essentially adopt Mexican mining law then in effect in California. The Mexican law gave the right to mine to the first one to discover the mineral deposit and begin mining it. The area that could be claimed by one person was limited to that which could be mined by a single individual or a small group.