His son, J. H. Belknap, was involved in promoting a toll road over McKenzie Pass in the early 1870s.

In 1975, louvered windows were added to the south side of the structure to improve the bridge's interior light.

[2][5] Because of its unique scenic beauty and its importance to Oregon's transportation history, the Belknap Bridge was listed on the National Register of Historic Places in 1979.

Its wooden floor planks and shingled roof are in good condition, as is the weatherboard housing that protects the Howe truss infrastructure from the elements.

The trusses have central beams and crossed timbers with adjustable, vertical iron rods to support the structural load.