The researchers studied sediment sources, erosion, and transport in the upper Yuba River watershed in California. They found that areas with low vegetation, steep slopes, erodible geology, and high road density have high erosion potential. Mass wasting is the main erosion process, but fluvial erosion is the main contributor to sediment yield. The South Yuba River carries more and coarser sediment than the Middle Yuba River due to its larger drainage area. Bed-load makes up a small percentage of the total sediment load in both rivers. Dry conditions during the study period may affect the accuracy of the calculated annual sediment transport.