Pend Oreille River 1920s, there was a proposal to divert the Pend Oreille through a gravity canal to irrigate the Grand Coulee and surrounding lands in eastern Washington as part of the tentative Columbia Basin Project. These plans were later dropped with the construction of Grand Coulee Dam and a pumping plant on the Columbia River. Variant names, according to the USGS, include: Bitter Root River, Bitterroot River, Clark Fork, Clarke Fork, Clarkes Fork, Clarks Fork, Deer Lodge River, Hell Gate River, Missoula River, Pend d'Oreille River, Silver Bow River, Clark's Fork, and Pend-d'Oreille River. Pend Oreille River The Pend Oreille River (
Grand Coulee wide as Niagara Falls and three times as high. Steamboat Rock high and a in area, now stands as an isolated rise, but for a time it created two cataract. When the falls passed north of Steamboat Rock, it found a granite base beneath the basal flows. Granite lacks the close vertical joints of basalt, was resisted the erosion from the cataract's plunge. It remains as hills on the broad floor of the Coulee. Some gravel-bar deposits are visible along the Route 155. They provide evidence of eddies in the lee of rock shoulders. Dry Falls is at the head