Twin Falls run year-round for one very good reason: the area around North Bend receives more than 90 inches of rain each year. Seattle--just 35 miles west--gets half that much. The South Fork Snoqualmie River takes that massive amount of rainfall and puts it to use entertaining hikers. The river squeezes into a narrow rocky gorge before tumbling over a very impressive stairstep falls. Then, when the water has been churned into a frothy torrent, it plunges over a 150-foot rock wall, creating the stunning cascade of the Lower Twin Falls.