Surface of the Owens Dry Lake. Pink salt lakes and playas, and the bright red evaporation ponds of salt recovery plants, are among nature's most remarkable biological phenomena. The red coloration is caused by astronomical numbers of microscopic, unicellular organisms living in the water and salt crust. Sierra Nevada, Inyo County, California,.© march. 1 2007 Marco van Middelkoop/Aerophoto-Schiphol