I've driven past this spot on AZ89 for a few years but never had time to stop. This year I was just to the South doing some Amateur Radio and since the weather was so nice decided to stop and take some panoramas.
This bridge dates back to the early days of motor vehicle traffic in the Southwest. Built in 1923 it slightly predates the establishment of the numbered US Highway System (1926) and at the time this was known as the Ash Fork Stagecoach Road. The bridge was added to the National Historic Register in 1988.
It is a 2-span Warren Deck Truss design and has a companion railroad span (still in use) from the Sante Fe Railroad on its West side.
The Little/Big Hell Canyon complex in this area has resulted in numerous bridges being built and abandoned over the years as routings and weight requirements have changed. This bridge is still in local use but the original alignment of US89 between Ash Fork and Prescott have been largely abandoned in favor of more modern (and safer) construction. You can see the bridge's replacement to the East where a culvert was built and a dirt berm was filled-in across the canyon.
If you have a day to explore, this area will not disappoint.