Yuba Goldfields

[2] In total, more than one billion cubic yards (760×10^6 m3) of river sediment and lesser hydraulic mining debris was dredged to produce an estimated 5.14 million ounces (146×10^6 g) of gold.

Wild turkeys, deer, ducks, Beavers, herons, bald eagles, Northern river otters and even mountain lions now live in the goldfields.

The first Yuba-area miners panned for gold in stream beds in the valley, but within a decade large-scale industrial processes replaced solitary prospectors.

After the miners extracted gold in long wooden sluices, they dumped the remaining sediment slurry back into the mountain valleys.

And while historic upstream hydraulic mining did result in the deposition of 10 to 40 feet (3 to 10 m) of hydraulic mining debris (slickens) in the area of the Hammonton dredge field,[1] these slickens were considered uneconomical at the time (because they had already been processed for gold once), and the primary target of gold dredging was the native river sediments (alluvium) of the Yuba River.

To that point, a vast majority of the more than one billion cubic yards of material dredged[2] was native alluvium, not hydraulic mining debris.

The dredgers also created over 200 ponds, which are fed by a network of underground rivers, which in turn were formed due to the porosity of the ground.

[6] In the twentieth century, a series of mining companies reprocessed the tailings, extracting gold that was increasingly difficult to separate from the gravel.

[7][8] The Goldfields is the largest aggregate mine in the State of California,[9] as well as one of only two dredge gold-mining operations in North America (as of 1989).

Salmon die when they reach fresh water, and their carcasses pile up in the goldfields, where turkey vultures hope to scavenge.

[6] As of September 2016[update], discussions were still ongoing, with the latest proposal being a habitat restoration project led by the United States Fish and Wildlife Service.