The Santiam Wagon Road was a freight route in the U.S. state of Oregon between the Willamette Valley and Central Oregon regions from 1865 to the 1930s. It is considered one of the most important historical routes in the state. Officially known as the Willamette Valley and Cascade Mountain Wagon Road, the Santiam Wagon Road was built between 1861 and 1868 and operated as a toll road until 1915. In 1925, the toll road was turned over to the State of Oregon for use as a highway. U.S.