The purpose of these maps is to provide the regional geochemical framework for the U.S. Geological Survey's Conterminous United States Mineral Assessment Program (CUSMAP) for the Richfield 1° x 2° quadrangle. The regional sampling is designed to provide definition of broad geochemical patterns and trends which can be utilized along with geologic and geophysical data for the assessment of the mineral resource potential for this quadrangle. These maps show the regional distributions of molybdenum in two fractions of heavy-mineral concentrates of drainage sediments for the Richfield 1° x 2° quadrangle.