In rivers, gold will concentrate in areas where the water velocity decreases. But, gold moves when the water velocity is high. Therefore, imagine what the water flow would look like AT FLOOD STAGE, and try to identify areas where the water velocity would decrease. Typical areas would be in front of large boulders, on the insides of curves, along the banks, etc.
South Yuba River State Park in Nevada County, California consists of the 22-mile long South Yuba River Canyon running from near Edwards Crossing to Bridgeport and contains some 2,000 acres. The park is noted for its historical gold mining connections and for the number of 19th century crossing bridges built along the length of the river. The area includes the longest single-span covered bridge in the world.