Columbia RiverJoin us as we start our expedition by paddling up the Columbia River Snake RiverUpriver gets harder as the lakes disappear and the current strengthens Yellowstone RiverThe Yellowstone is the longest free-flowing river in the continental US. Its spring and we are heading downriver. Missouri RiverMississippi RiverOhio RiverTennessee RiverLittle Tennessee RiverSavannah River