U. S. Geological Survey Party No. 4 mapped the stratigraphy and structure of parts of the Carbon Creek and Ketik anticlines during the summer of 1950. The area, which lies in quadrangles I-19 and I-20 is shown in figure 1. Large-scale maps, compiled from plane-table surveys, give a more detailed picture of two parts of the area, the west plunge of the Carbon Creek anticline (fig. 2) and a segment near the middle of the Ketik anticline (fig. 3).