As the title suggests, the subject matter in this book deals for the most part with the examination and testing of placers. It is intended primarily as a guide for the professional mineral examiner who examines mining claims located on public lands of the United States.

California has been the source of more than 106 million troy ounces of gold, the most productive state in the Union. This digitized publication by the California Division of Mines & Geology contains information on approximately 350 gold mining districts.

This is part two of a series of articles from the Book "Principal
Gold-Producing Districts of the United States" published by the USGS.

This is part one of a series of articles from the Book "Principal
Gold-Producing Districts of the United States" published by the USGS.

The sources of data for the gold worksheet are the mineral statistics publications of the U.S. Bureau of Mines (USBM) and the U.S. Geological Survey (USGS)—Minerals Yearbook (MYB) and its predecessor, Mineral Resources of the United States (MR); and Mineral Commodity Summaries (MCS) and its predecessor, Commodity Data Summaries (CDS)