Geologic mapping within the Quill Creek area identified complex stratigraphic and structural relationships that characterize much of the Kluane Ranges in southwest Yukon. Bedrock in the Quill Creek area consists of Late Paleozoic to mid-Mesozoic volcanic and sedimentary rocks belonging to the Wrangellia Terrane. These rocks are intruded by Upper Triassic mafic and ultramafic sills and dykes and Early Cretaceous to Oligocene granitic rocks. At least two phases of folding are recognized that affect rocks throughout the mapped area. Early phase folds are likely associated with large, low-angle thrust faults. Reactivation of thrusts during younger strike-slip faulting may be responsible for refolding of the early folds. Several known mineralized showings occur within the Quill Creek area, including extensive nickelcopper- platinum group element mineralization associated with the ultramafic sills. Samples collected during 2004 mapping indicate potential for copper-silver mineralization at the base of Upper Triassic volcanic rocks.