Abstract Each of the sedimentary basins of the Rocky Mountain province is geologically unique. All have been structurally controlled but by different episodes and styles of tectonic activity. At least some of the structures have been reactivated one or more times during the Phanerozoic. Because of the great geologic diversity, no one worker could be authoritative about the geology of the province. Consequently, each basin in this chapter has its own specialist authors. They are identified with their appropriate texts and listed at the beginning of this chapter. Although an attempt has been made to standardize the format of the basin subchapters, some differences in style and geological focus appropriately reflect the differences among the various authors. Little attempt was made to force uniformity in details of approach to the basin analyses. Organization of the chapter is geographic. Basins west of the Rio Grande Rift system are stratigraphically more closely related to the Cordilleran miogeocline than to the craton and are treated first. These basins are described in order by age, and geographically from south to north. Those basins lying east of the Rio Grande Rift and more closely related to the craton are presented in order from south to north. Prior to Pennsylvanian time, the site of the modern Rocky Mountains was largely that of a broad, shallow marine shelf at the inner margin of the Cordilleran miogeocline. Late Paleozoic basins developed concurrently with the uplift of the Ancestral Rocky Mountains as the Precambrian basement structural fabric was strongly reactivated

Abstract Three vantage points from which to view the Teton mountain front are discussed (Figs. 1, 2) all in Grand Teton National Park, Teton County, Wyoming. Site 1 is in the NW¼NW¼ Sec.26,T.44N.,R.115W. (U.S.G.S. 7½-minute topographic map of Moran Quadrangle, 1968). Site 2 is in the NW¼SW¼SW¼ Sec.1,T.43N.,R.116W. (U.S.G.S. 7¼-minute topographic map of Moose Quadrangle, 1968). Site 3 is in the center SE¼ Sec.12,T.44N.,R.116W. (U.S.G.S. 7¼-minute topographic map of the Jenny Lake Quadrangle, 1968).

Abstract Red Grade viewpoint is in the SW¼ NW¼ SE¼Sec. 8, T.5N., R.SW., Wind River Meridian, 17.3 mi (28 km) southeast of Dubois, Fremont County, Wyoming, Blue Holes and Wilderness 7½-minute Quadrangles (Fig. 1). Figure 1. Index map showing location of Red Grade site. Geology of area between Dubois and the Red Grade site is described on the road log.

Abstract Oil and gas have been known in nonmarine Tertiary rocks in Wyoming since 1896. Commercial oil or gas pools have been discovered in Paleocene and Eocene rocks in the Green River, Washakie, and Wind River basins. The source of most of this oil and gas is believed to be sediments deposited under lacustrine conditions during Paleocene time and again during Eocene time. Oil and gas production from nonmarine beds of latest Cretaceous age is a recent development. The diastrophic and depositional history from latest Cretaceous through Tertiary time has a significant bearing on essentially all Wyoming oil and gas fields. The Laramide orogeny began with gentle folding in latest Cretaceous time, reached a climax of intense folding and thrust faulting in earliest Eocene time in most parts of Wyoming, and was essentially completed by latest Eocene time. Conventional Wyoming oil and gas fields are those related to structural traps formed during this orogeny. The Green River, Wind River, and Hanna basins were sites of deposition of more than 20,000 feet of latest Cretaceous, Paleocene, and Eocene strata. Oligocene, Miocene, and Pliocene beds were deposited across the now completely filled basins and high onto the flanks of partly buried mountains. Volcanic debris from centers within or near Wyoming comprises the bulk of these young strata. Regional uplift, large-scale normal faulting, and rapid degradation that exhumed the mountains and re-excavated the basins occurred in late Pliocene and Pleistocene time. During this episode some of the structures containing oil and gas were significantly modified.