River Pass is a place in the U.S. state of Colorado.
A rather peaceful, idyllic small town enters into a period of chaos when the Horseman War decides to invade it. War destroys the town's bridge upon arrival, pollutes the river and kills a local man named Roger and assumes his form. Using his powers, he drives the locals into believing demons have taken over the town and have taken possession of various members.
This draws in the attention of a number of hunters, namely Rufus Turner, Ellen and Jo Harvelle, and eventually Sam and Dean Winchester. It is soon discovered who is behind the disruption, and Sam and Dean try to convince their friends of the cause in order to avoid further bloodshed. The brothers confront War and remove his ring, forcing him to flee and be reduced to a "withered husk".
With War gone, the town returns to normal, albeit with many members dead.