Native American Salt Basins in the Sierra Nevada

Native Americans of the Miwok tribe in the northern Sierra Nevada, California carved these basins into the granite bedrock to produce salt for trade. They filled the basins with water from a salt spring and let the water evaporate, leaving a salt residue in the basin. Jim Moore, USGS geologist, looks east along a salty stream that has bleached the bedrock adjacent to the stream in the left side of the picture. Healthy lichens and more angular bedrock occur away from salty stream on the right.