The River Pass War was a conflict between the Horseman War and infected townspeople against Hunters and the resistance fighters.
Battle[]
Rufus Turner calls Bobby Singer on a walkie talkie from River Pass, Colorado, about an infestation of demons. In no condition to fight, Bobby sent Dean and Sam to check it out. They hike in out of the boundaries because the bridge is down and run into Ellen Harvelle, who tests them and leads the way back to headquarters. There is a group of samaritans hold up here lying low because the last time they made a break for it 20 of them were killed by the demons. Sam goes to scout for Jo and gets captured and when he looks at them their eyes are black, but to them his eyes are black, so something is not right. "Roger" takes off his mask and reveals himself as War, meaning he was a wolf in sheep's clothing. Sam and Dean ambush War and take his ring before he can do it to the next town, and it's like everyone wakes up out of a nightmare.
Aftermath[]
The concept of war is still a constant in the world and can't be gotten rid of that easy even though they put down War incarnate. Sam said it's for the best to go their own ways and Dean thinks its the right thing to do, but tells his little brother to watch his back.