It has been pointed out that several features or bends of the American River are not illustrated. I don’t believe it was the intent of the map maker to accurately depict river but to note its relative position to the mines. The distances of 25 miles to the lower mines and of 50 miles to the upper mines is pretty accurate. The lower mines were also known as Mormon Island for the first group of miners who did extensive mining after the initial discovery of gold by Marshall. The distance to the upper mines, site of Marshall’s gold discovery is also relatively accurate considering hilly terrain that had to be traversed to get to the location.