Nellie Falls is the major waterfall of the Middle Fork Snoqualmie River. Located near the Dutch Miller Gap trailhead, the falls occur where the river drops over a headwall in the valley, and thunders down a series of steep cascades. Even when the river is at it's lowest volume late in the summer, these falls are still very impressive. During the peak of spring melt, however, this waterfall becomes a massive sheet of violent whitewater, sending spray high into the air.