Loved your layout! A midwestern spin on a fantasy world was something I was not expecting to see but here we are! I was trying to confirm in the writing if the adventurers are going down the river during the festival proper, or before it because the riverlanders wanted the problem to be solved before it started, but I couldn’t find any conclusive info on that. I would lean towards the adventure happening during the run! The shift from festival to serious problem is a lot more attractive to me :) Rivers are definitely not done enough justice, specially considering their importance in pre-industrial civilizations. Nice work!