Spring River Marsh Arch Rainbow Bridge
The former Spring River Marsh Arch Rainbow Bridge was on the westbound lanes (at the time it was built, they were the only lanes). It were 3 consecutive spans. The bridge on the eastbound lanes is an early 1960s bridge added when the 2 lane highway was made a divided highway.
The last remaining Rainbow Arch bridge on Route 66 is just a bit to the west on the other side of Riverton.