The Missouri National Recreational River preserves a one-hundred-mile stretch of North America's longest river as a vestige of the untamed American West. Two free-flowing stretches of the Missouri make up the national park, offering exploration of a wild, untamed, and mighty river that continues to flow as nature intended. Rapid weather changes are common along the river corridor, with great seasonal and yearly variation. The climate is characterized by hot summers, cold winters, abundant sunshine especially in summer, average annual rainfall of 25 inches, dangerous thunderstorms especially from June until late August, and average annual winter snowfall of 34 inches.