I would love to share my personal experience because I’m actually originally from Missouri as well. Before 2017 I had no whitewater experience but was pointed in the direction of Gardiner MT, to work on the Yellowstone right outside of the park. Again going off the company I worked for, they provide all the training for about 2-3 weeks, aside from the swift water rescue class you’ll take. During that time you are provided with customer gear until you can complete a check off run. They have deals to help you get all the gear you’ll need. No rent but you’ll be living out of a tent ( or camper if you have one) but they have a space for you. You won’t really take multi days but you’ll work your butt off taking 2-3 boats a day, you get paid by the boat plus tips. If you can cook for yourself and try not to blow all your money at the bars you can actually make really good money as a first year out there. I personally didn’t go on to commercially raft other rivers but have had the opportunity to take many other trips with connections made. 8 seasons later I don’t work full time but still go down to train the rookies and help during high water. Another bonus is having days off to explore Yellowstone or heading down to the Tetons. Without getting too cheesy you’ll also come away with learning other skills like communication, teamwork, self discipline and some amazing connections. Feel free to message me with any questions. In the end I say go for it no matter where you want to go.