Alright kiddo, so the Clark Fork River is a big body of water that flows through a place called Montana. It's kind of like a really long snake that moves and twists around. People like to go to the river to do fun things like swimming, fishing, and kayaking.
But the river didn't just show up out of nowhere! A long, long time ago, glaciers (which are HUGE pieces of ice) moved across the land and shaped the area where the river is now.
And you know what? The Clark Fork River is really important because it provides water for a lot of people and animals around there. But sometimes, people can accidentally put bad things into the water that can make it not safe for anyone to use. That's why we have to be careful and take care of the river, so that everyone can enjoy it for many years to come!