This article and a more detailed guidebook (free PDF download) explores the spectacular calcretes of south-central Washington. The thick, bright white CaCO3-rich paleosols overprint the Pliocene Ringold Fm, Plio-Pleistocene fanglomerates, pre-Wisconsin flood gravels, and early Palouse loess. The blanket-like hardpans formed in alluvial sediments low in the landscape where strong evapotranspiration moved large volumes of water through the soil column via vegetation rooted near