This might be an idea for when you have more time. Take a ‘mailboat’ ride on the Rogue River in Oregon. There are several whitewater sections that are navigated on the river and trips go up to 100 miles in round trip.
Not the cheapest, but might be interesting and there is beautiful scenery along the way. When I went, they were using special boats, low draft when on plane (about 3″), 3 large Chrysler engines driving 3 Jacuzzi jet drives. I was able to sit/stand in the back with the driver and learned a lot about navigating the river from him.. but that was before all the sue-happy-lawyer types came into being. I would try to get the front right or left two seats in the front two rows as a preference.. or if not that, the seats along the sides (that is if you don’t mind possibly getting wet – bring raincoat/slicker). If you bring a camera, have some sort of water-resistant/proof container for it if you go on the whitewater sections.
Crater lake, Klamath river etc are not to far away either.