This bridge, if it was used by the DRI line, is not from the Interurban Clinton, Davenport and Muscatine Railway. It is from the Burlington, Cedar Rapids, and Northern line from Stockton to West Davenport that also followed Blackhawk Creek toward Westlake Park, also known as railroad Lake. This line was abandoned by The Rock Island lines in about 1928 as being unnecessary as there was little or no local traffic generated in Blue Grass, and the main line already ran from Stockton into Davenport.
If you trace the ROW westward from this spot using the GIS link below or historicaerials.com, you'll see that the trestle is indeed on the CD&W's ROW. as you'll see it crossing the Rock Island's Stockton-West Davenport line on the CD&M's overpass at what is now West Lake Park.
The trestle became an industrial spur on the DRI-Line at some point after the CD&M folded.