The Yuba Goldfields, also known as the Hammonton dredge field, is the largest gold dredge field in California. Located along the Yuba River approximately upstream of the town of Marysville, in Yuba County, the Hammonton dredge field was actively dredged for gold from 1904 to 1968. In total, more than of river sediment and lesser hydraulic mining debris was dredged to produce an estimated of gold. The goldfields are noted for their otherworldly appearance (a result of gold dredging operations), filled with roughly linear mounds of gravels (called dredge tailing windrows), ravines, streams and turquoise-colored pools of water. From the air, the goldfields are said to resemble intestines.