Sacagawea history and The Snake River Valley
The cities of Lewiston and Clarkston were lucky enough to be far enough away from the nukes. However they were situated on excellent communications routes and were in danger of being swamped by refugees.
Law and order rapidly collapsed – only the State College functioned as a provider of (tenuous) stability and government. The two cities were dying – until the the second winter after Death Day – when the tribes came off their reservations and brought food and security.
Of course, there was a price: the citizens of Lewiston and Clarkston had to become part of the Nez Perce nation. Since that date, the cities were amalgamated and named after the Amerindian woman who guided the Lewis & Clark expedition. The Lewis-Clark State College became a junior partner in government.
The Amerinds fed the cities and led the fight against others who wanted to control the Snake River Valley and the Clearwater River. The Frozen Chosen were the first to challenge the Amerindian dominance of the agricultural treasure-house that is the Snake River Plain. In fact, if it was not for the need to fend off The Frozen Chosen, there may not have been an Amerind Empire.
Sacagawea has dealt with a number of potential enemies since then. The most recent are the pseudo-scientists known as the Breeders – who are responsible for a low-level campaign of kidnapping and brigandage.
The Amerind Empire trades food, chemicals and manufactured goods with Bikers, Gypsy Truckers and (indirectly) with the Frozen Chosen – via a group known as the the River Gypsies.