DESCRIPTION: The San Francisco Mining District was organized in the San Francisco Mountains of Beaver County on 12 August 1871. The following year Congress passed a general mining law validating the already established precedent that mineral deposits in the public domain were free and open to exploration, and locators have exclusive right of possession (Statutes at Large, Treaties, and Proclamations, of the United States of America, vol. 17, 1872, chap. 152). In local areas groups of miners organized districts to manage mining activity and keep records of claims. San Francisco Mining District Record Book A begins with a copy of the by-laws and an index (chronological list of claims recorded in the book). These are followed by notices of location, or mining claims. Since early claims were limited to 200 feet along a lode, several locators were generally listed on each claim. Location notices generally identified a claim by a unique name and provided a description of its location and dimensions. Each location notice was dated and signed by a San Francisco Mining District recorder or deputy. Early location notices also included, on the same page, validation that assessment labor has been completed. Later books include a variety of additional mining related documents. These include affidavits offering proof of the completion of annual assessment labor, and 'exemptions' filed in 1893-1894, when Congress temporarily suspended the requirement for annual assessment work.