Rainbow Falls, Montana

Rainbow Falls is a waterfall on the Missouri River in Great Falls, Montana, just upstream from Crooked Falls and downstream from Colter Falls and Rainbow Dam. It is 47 feet (14m) high and 1,320 feet (402.3m) wide. The waterfall is part of the five Great Falls of the Missouri. The river spills over a sheer ledge of sandstone in the Kootenai Formation, forming the falls. The falls used to flow with a great deal of force year-round. In 1914 the river shortly upstream was dammed for hydroelectric power by the Rainbow Dam, which forms a run-of-the-river reservoir. As a result, the falls can almost totally dry up in the summer with only a few narrow strips of water trickling down its face. A railroad bridge crosses the river directly above the falls.