"About two million years ago, toward the end of the Tertiary geological time period, the mountain systems in the western United States (and throughout all of the Americas - Stan) underwent a tremendous amount of faulting and twisting, changing the character of the mountains into much of how they look today. It was during the same period when the present drainage system of streams, creeks and rivers were formed, which run pretty much in an east / west direction."

"Prior to that, there was a vastly different river system, which generally ran in a southerly direction. These were the old streambeds which ran throughout much of the Tertiary period, and so are called "tertiary channels" or "ancient rivers." The ancient rivers ran for millions of years, during which time an enormous amount of erosion took place, washing enormous amounts of gold from the exposed rich lode deposits into the rivers.

"The major changes occurring towards the end of that period, which rearranged the mountains and formed the present drainage systems, left portions of the ancient channels strewn about. Some portions were placed on top of the present mountains. Some were left out in the desert areas. And some portions were left close to, and crossed by, the present drainage system.

"Geologists have argued that most of the gold in today's river systems is not gold that has eroded more recently from lode deposits, but gold that was eroded out of the old ancient riverbeds where they have been crossed by the present river systems.

"The ancient channels, where they have been discovered and mined, have often proven to be extremely rich in gold deposits. In fact, many of the richest bonanzas that have been found in today's river systems have been discovered directly downstream from where they have crossed the rich ancient streambed gravels."

Dave McCracken

Gold Mining in the 1990's

The Complete Book of Modern Gold Mining Procedures