The Green River Formation of the Western United States is famous for several unusual mineralogic and geologic features, some of which are favorite arguments used by anticreationists against the biblical timescale. The uniformitarians believe that the couplets in the Green River Formation are varves, but evidence militates against this interpretation. Many creationists are also convinced that some of these features cannot be explained by the global Flood of Genesis but must instead be the result of longer-term processes after the Flood. Evidence from erosion and geomorphology, however, militate against the postdiluvial view and is more favorable of a catastrophe on the scale of the Genesis Flood.