If you want to see a little bit of Arizona history still in use, look no further than the Hassayampa Bridge, located at coordinates N 34 18.627 W 112 34.086.
This bridge was built in 1924 as permanent wagon bridge over the Hassayampa River. It is the earlier of the only two camelback through truss design in Arizona remaining.
It was built by the El Paso Bridge and Iron Company out of Texas at a proposed cost of $7,800 (not sure if they met budget or not). The construction is steel trusses with a wood deck. It is the only bridge in Arizona that combines through and pony truss spans.
Driving over the one lane bridge may be a little scary for some (though the drop isn't too far) knowing this bridge is close to 100 years old.
Don't fear. There's is a short bypass for heavy / tall trucks. You can access the bridge from below (on foot) from this bypass road. While we were under the bridge, a car drove over. It sounded loud and dramatic but I watched the planks, beams and trusses. None of the budged. It appeared solid as the day it was built.
This bridge can be a neat spot for history/engineering buffs. If you're in the area, you may want to check it out.