The coal-bearing Dakota Sandstone at Coal Canyon, Arizona, which is located in the western portion of the Black Mesa basin, has yielded abundant, diverse, and generally well-preserved spores, pollen, and microplankton. The formation is characterized by high frequencies of fern spores, especially striate spores belonging to the Schizaeaceae, and angiospermous pollen consisting primarily of simple tricolpate and tricolporate grains. Gymnospermous pollen is comparatively uncommon. The microflora assemblage contains many exclusively Cretaceous species previously reported from Australia, western Europe, Siberia, and other localities of North America. A microflora which compares closely with the Dakota assemblage occurs in the Woodbine strata of Oklahoma. On the basis of palynologic evidence, the age of the Dakota Sandstone at Coal Canyon, is interpreted as lowermost Upper Cretaceous (Cenomanian).