In the vicinity of Great Falls, Montana, there are some very large springs which present unique geologic features and an interesting question as to the source of the water. These springs, which are locally known as the Giant springs, are located on the south bank of Missouri river, about 3 miles below Great Falls. They have a very large flow of relatively pure water, which appears at the surface through large joint planes in a medium to coarse grained sandstone belonging to the Kootenai (Lower Cretaceous) period. For a short distance on either side of the main spring there are smaller springs flowing from the joint planes, and directly opposite it, in the bed of Missouri river, there is another large spring, which is only apparent during low water seasons.
Previous workers in treating the geology of this region have made only brief mention of the occurrence of these . . .