Existing comment:
Hydraulic mining was one of the cheapest methods to recover gold from river gorges. One or two men could process hundreds of tons of earth daily, making it practical to mine very low grade gravels.
Monitors directed huge jets of water at hillsides washing soil, sand and gravel down through a series of sluices that caught the heavier gold bearing particles. The muddy tailing drained into streams, lakes and rivers. This waste eventually overwhelmed the waterways and brought court injunctions that ended hydraulicking in 1884.
Malakoff Diggins State Park is the best surviving example of a hydraulic mining site. |