Clay, mud, silt, cross-bedded sand, and pebbles were later deposited by meandering streams and in flood plains, forming the locally 100 to 500 foot (30 to 150 m) thick Salt Wash Member. Claystone and mudstone beds of this member erode into gray slopes that can exhibit brown, red, yellow, and green colors. Salt Wash sandstone is moderately sorted and fine to medium grained while pebble conglomerate beds are made of chert with small amounts of silica-rich limestone. Both bed types erode into ledges and small cliffs. The Salt Wash was locally mined in the 1950s to extract uranium ore.