Powder River Basin
The Powder River Basin is an elongated (150 by 360 km2) structural basin, bounded by the Big Horn Mountains and Casper Arch on the west, Miles City Arch to the north, Black Hills uplift to the east, and the Hartville uplift and Laramie Mountains to the south, located in the northeast Wyoming and eastern Montana. During the Paleozoic and Mesozoic era, the Powder River basin was part of the paleo-Williston Basin. The present configuration of the basin is the result of Late Cretaceous and early Tertiary deformation (laramide orogeny). The entire sedimentary fill in the basin is approximately 4,300 m. Two Elk Energy Park is located on the gently-sloped (<2o to the southwest) side of the basin. Five regional aquifer systems, with variable salinities, are known in the basin (USGS, 1996).
