The Powder River basin of northeastern Wyoming is a basin of the broken foreland between the stable interior of the craton and the Cordilleran orogenic belt. The formation of the basin reflects the complex depositional history of both regions. The rock strata within the basin may be divided into tectonostratigraphic units that allow interpretation of basin evolution within a plate-tectonic context.

During Precambrian to Late Devonian time, the area occupied by the present-day basin was transitional between the craton and the rifted margin of the continental shelf to the west. The basin area occupied a complex setting peripheral to foreland basins and the stable continental interior during the Antler orogeny (Devonian-Mississippian), Humboldt orogeny (Pennsylvanian-Permian), Sonoman orogeny (Permian-Triassic), and Nevadan stage of the Cordilleran orogeny (middle Late Jurassic). After the beginning of the Sevier orogeny in the Late Jurassic, the area was within the Cretaceous retroarc foreland basin. The first indication of subsidence within the basin is late in Laramide time (Paleocene); subsidence continued through at least early Eocene time. Stream drainages in Paleocene to ear y Eocene time were dominated by rising highlands, which produced a north-flowing trunk stream. During much of the Paleogene, this drainage was connected to the Wind River basin on the southwest.

A-type subduction of the cratonic margin beneath the rising magmatic arc in the western batholithic belt, following collision of exotic terranes during a period of increased movement of the craton relative to the Pacific plate, was the most probable cause for events of the Cordilleran orogeny. Laramide-style basement-block uplifts express the extension of the thin-skinned tectonics in the western orogenic belt eastward into the thicker lithosphere of the foreland along the craton margin, possibly during overriding of an aseismic ridge on the Pacific plate by western North America. Uplift and erosion of the basin since early Eocene time may be due to thermotectonic uplift around the apices of the Snake River plain and the Rio Grande rift.

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