Only the richest ores could be worked and shipped off for processing at a profit. As a result, early mining in the southern part of the Humboldt Range was short-lived. In the 1880s, placers were discovered in Spring Valley and American Valley on the east side of the range...

Geology is a science of general tendencies with frequent exceptions, not one of hard and fast rules that are always true and never vary. For almost every well-accepted rule of gold deposits, I can point you to a number of important exceptions.

The Oatman/San Francisco Mining District’s historic gold production of 2.2 million ounces of gold since the 1880s makes this area Arizona’s greatest primary gold producing district.

Not all of these slides and debris flows will produce results, but if you search for these while prospecting in your gold producing areas, then you can increase your odds of finding new gold.

Gold is a fairly widespread mineral in the Italian Alps and in the Northern Apennines. It is found both in primary mineralization and in past and recent floods.