This book is for those who want to know more about the Payette and Idaho Northern branches of the Oregon Short Line, later Union Pacific, and today the Idaho Northern & Pacific Railroad. It is based upon a route history written for an all-day exploration of the railroad between Payette and Cascade, conducted using a charter passenger train, and helps to answer the question Where are we and what once happened here? The Payette and Idaho Northern branches started as efforts to reach farms and forests along the Payette River in Idaho. The rail line eventually reached far into the Payette National Forest, serving as a conduit for the movement of timber and lumber, livestock, and agricultural products. Today, parts of the line have been abandoned, but much of it is still owned and operated by the Idaho Northern & Pacific Railroad. This book provides information on the railroad’s history, as well as a mile-by-mile route guide.