South across the Montana Plains and a Missouri Crossing

Monday
I would associate the Missouri River with the Mid West, a river just above the Mississippi. But no, the Missouri rises in the mountains south of Glacier National Park. Today we crossed the Missouri.
Not only did we cross the Missouri we also crossed it where the famous Lewis and Clarke passed by (well I suppose they traveled most of the Missouri River, so I suppose we would cross it where they passed. We set out from East Glacier and traveled south, parallel to the mountains, amazingly the mountains did not end at the Glacier National Park, but continued southwards forming a solid wall of rock for over a hundred miles. It mus have been quite daunting for Lewis and Clarke to have traveled for over a thousand miles on flat land (well river) and then to see this mountain range fill the entire horizon from north to south. However they had a plan, follow the river to its source, then hop over the Continental Divide to travel down a river on the other side, this would be the Columbia River, the river we have more or less followed Eastwards.
The land we now drove through was mostly flat, gentle green hills, though as we approached Wolf Creek the hills began to become higher and higher. we stopped at a State Recreation Area, beside a lake formed by damming the Missouri. It was another lovely campground, where we overlooked the lake, no forest this time, just some nice cottonwood trees for shade.
We decided that we would stay here two nights and recharge the batteries.