In 1882, the Oregon Railway & Navigation line running from Cascade Locks to Portland was constructed. The railroad ran just beside the river and a few feet above it. In the process of the railroad's construction, the road of 1876 was largely destroyed.
Corporate history is complex on this one:
Oregon Steam Navigation Co. 1863-79
Oregon Railway & Navigation Co. 1879-86
OR&N Leased by UP 1886-88
OR&N jointly leased by UP & NP 1888-89
OR&N leased by UP 1889-94
Oregon Railway & Navigation Co. (Independent) 1894-96
Oregon Railroad & Navigation Co, 1896-1900
ORR&N (Subsidiary of UP) 1900-1910
Oregon-Washington Railway & Navigation Co (Sub of UP) 1910-36
OWR&N (Leased and operated by UP) 1936-87
Union Pacific Railroad 1987-Current