The Duer Ranch locality is situated on either side of U.S. 26 in southeastern Merrill County, Nebraska, halfway between the villages of Lisco and Broadwater and about 54 mi (90 km)southeast of Scottsbluff, Nebraska. The Rush Creek Land and Livestock Company currentlyowns all of sections 28, 29, 33, 34, and 35 of T. 19 N., R.47 W., as well as parts of sections 2, 3, 4, 10, and 11 of T. 18N., R.47W. (Broadwater and Tar Valley SW, 7½-minute Quadrangles; Fig. 1). The owners have allowed geologists to study the exposures on ranch property providedthat visitors stop at the...