For context, waterways are all public land but river banks for some reason aren't.
Many local governments ban camping or harass campers, and many areas have been taken over by waterfront millionaires who think they own the river.
The river is feral land, so a federal permit (genetic, automatically granted) actually supercedes municipal bylaws.
That's why I wouldn't just pitch a tent on the river bank, especially in coastal areas.
The river is also far longer than any national park, and id like to travel down the entire river over a couple of months. I can stay at a few camping ground along the way which will operate as resupply points.