The original plan was for a mostly sincere ~1950 single deck Milwaukee Road single track mainline with 11'+ passing sidings from Roland, ID to Puget Sound with some compression and mostly 48" aisles. Since 2015, the benchwork for a sidingless NP double track main to Portland has been added and a lower level created to add very insincere aisle-hopping Great Northern runs to Vancouver, BC, and Spokane with about 7' passing sidings. The UP will run Portland to Seattle via NP and Milwaukee; and to Spokane via SP&S.
Published sources: Mainline Modeler, Model Railroader, N Scale Enthusist, N Scale Railroading, and N-Scale Magazine.
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