(Written by Colonel J.C. Fremont in 1847 (and updated in 1852) about his explorations and observations of California during the Gold Rush.)
One day Mr. Marshall, as he was walking down the race to this deposit of mud, observed some glittering particles at its upper edge; he gathered a few, examined them, and became satisfied of their value. He then went to the fort, told Capt. Sutter of his discovery, and they agreed to keep it secret until a certain grist-mill of Sutter's was finished. It, however, got out, and spread like magic. Remarkable success attended the labors of the first explorers, and in a few weeks hundreds of men were drawn thither. At the time of my visit, but little over three months after the first discovery, it was estimated that upwards of four thousand people were employed. At the mill there is a fine deposit or bank of gravel, which the people respect as the property of Captain Sutter, although he pretends to no right to it, and would be perfectly satisfied with the simple promise of a pre-emption, on account of the mill which he has built there at considerable cost. Mr. Marshall was living near the mill, and informed me that many persons were employed above and below him; that they used the same machines at the lower washings, and that their success was about the same--ranging from one to three ounces of gold per man daily. This gold, too, is in scales a little coarser than those of the lower mines.