Report of Investigation 2020-3, Geologic map of the Styx River area, Lime Hills C-1 Quadrangle, Western Alaska Range, Alaska, presents a 1:63,360-scale geologic map of the Styx River area (Lime Hills C-1 Quadrangle) in the western Alaska Range. The Styx River map area is underlain by Late Jurassic to Late Cretaceous Kahiltna assemblage sedimentary rocks. Major plutons include the Late Cretaceous South Fork gabbro and Mount Estelle monzogranite, the Paleocene Crystal Creek granite, McKinley sequence granites, Styx River granite, and the Eocene Merrill Pass granite. Major oxide and trace element data helped differentiate distinct compositions of plutons and refine map contacts. Late Cretaceous granodiorite to gabbro plutons contrast in composition with granites from the Paleocene. Previously unmapped mafic dikes trend generally northwest, while major high-angle fault sets trend northwest, north-south, and north-northeast. Mineralization in the Lime Hills C-1 Quadrangle is dominated by: 1) Au-Cu mineralization associated with the margins of the latest Cretaceous Mount Estelle pluton; 2) widely scattered Ag-bearing polymetallic occurrences associated with dikes, veins, and faults of a range of ages and; 3) the Miocene-age Copper Joe porphyry copper prospect. The dataset contains geologic, structural, stratigraphic, and geochronologic data organized according to the GeMS and AK GeMS mapping schemas. The complete report, geodatabase, and ESRI fonts and style files are available from the DGGS website: http://doi.org/10.14509/30424.