Task: Question Generation
Input (English): Passage: When the Gold Rush began, the California goldfields were peculiarly lawless places. When gold was discovered at Sutter's Mill, California was still technically part of Mexico, under American military occupation as the result of the Mexican–American War. With the signing of the treaty ending the war on February 2, 1848, California became a possession of the United States, but it was not a formal "territory" and did not become a state until September 9, 1850. California existed in the unusual condition of a region under military control. There was no civil legislature, executive or judicial body for the entire region. Local residents operated under a confusing and changing mixture of Mexican rules, American principles, and personal dictates. Lax enforcement of federal laws, such as the Fugitive Slave Act of 1850, encouraged the arrival of free blacks and escaped slaves.While the treaty ending the Mexican–American War obliged the United States to honor Mexican land grants, almost all the goldfields were outside those grants. Instead, the goldfields were primarily on "public land", meaning land formally owned by the United States government. However, there were no legal rules yet in place, and no practical enforcement mechanisms.The benefit to the forty-niners was that the gold was simply "free for the taking" at first. In the goldfields at the beginning, there was no private property, no licensing fees, and no taxes. The miners informally adapted Mexican mining law that had existed in California. For example, the rules attempted to balance the rights of early arrivers at a site with later arrivers; a "claim" could be "staked" by a prospector, but that claim was valid only as long as it was being actively worked.Miners worked at a claim only long enough to determine its potential. If a claim was deemed as low-value—as most were—miners would abandon the site in search for a better one. In the case where a claim was abandoned or not worked upon, other miners would "claim-jump" the land. "Claim-jumping" meant that a miner began work on a previously claimed site. Disputes were often handled personally and violently, and were sometimes addressed by groups of prospectors acting as arbitrators. This often led to heightened ethnic tensions. In some areas the influx of many prospectors could lead to a reduction of the existing claim size by simple pressure.
Output (English): What were the mining rules that established that a claim was valid only as long as it was being actively worked?