Originally determined eligible in the Caltrans 1985 Historic Masonry Bridges in California Thematic Resources study; its continued eligibility was confirmed in the 2003 Caltrans Historic Bridge Inventory update: Masonry Bridges. It is also included in the Sonoma County historic bridge thematic landmark.
The Calabazas Creek Bridge is a single span earth-filled grouted red-brick arch bridge. The bricks of the spandrel walls are laid in the 4-course American bond pattern (alternating 4 courses of stretchers to one course of headers). The voussoirs are placed in four header rows. The brick parapet railings have been capped in a protective coating of concrete.