It passes through the gap between the Sierra and Cascades and into the Snake River Plain where it is channeled through most of the Rocky Mountains with no high plateaus or mountain ranges to impede its progress.
Pasa a través da brecha entre a serra e Cascader e na chaira do río Snake na cal se canaliza a través da maioría das Montañas Rochosas, sen altas mesetas nin serras que impidan o seu avance.